JP3728279B2 - Optometry system and optometry program - Google Patents

Description

【００４９】
また、眼球光学パラメータ決定手段２８は、式２により、被検査者により正円形の視標２４ａの長さが最も長く視認された方向に配置された視標２４ａ、２４ｂの中心点間距離Ｄ１（視標が最も長く視認された方向における被検査者が視認した視標の長さ）を算出する。
【００５０】
【式２】

【００５１】
なお、眼球光学パラメータ決定手段２８は、被検査者により正円形の視標２４ａの長さが最も長く視認された方向θに直交する方向（乱視軸）に配置された視標２４ａ、２４ｂの中心点間距離Ｄ２（視標が最も長く視認された方向と直行する方向における被検査者が視認した視標の長さ）についても、式２に中心座標を入力することにより算出する。
【００５２】
概算レンズ度数決定手段３０は、眼球光学パラメータ決定手段２８により算出された視標の中心点間距離Ｄ１および中心点間距離Ｄ２により被検査者の概算レンズ度数を決定する機能を有する。概算レンズ度数決定手段３０には、視標の中心点間距離と被検査者のレンズ度数との関係について採取したデータに基づき、視標の中心点間距離から被検査者のレンズ度数を概算するためのテーブルが記憶されている。概算レンズ度数決定手段３０は、中心点間距離Ｄ１および中心点間距離Ｄ２に基づいて、乱視軸方向および乱視軸に直交する方向の被検査者のレンズ度数を概算する。
【００５３】
眼球光学モデル決定手段３２は、スタート眼球モデルを年令区分と概算レンズ度数とからスタート眼球モデルを選択するように構成されている。なお、スタート眼球光学モデルとは、縦軸に年令区分、横軸に概算レンズ度数区分を設け、それぞれの区分の中央値における眼球光学モデルをあらかじめ作成したものである。この実施形態においては、眼球光学モデル決定手段３２は、被検査者の年令と概算レンズ度数に基づき初期値としてのスタート眼球光学モデルを決定することができるように構成した。眼球光学モデル決定手段３２には、スタート眼球光学モデルデータベース（図示しない）が記憶されている。スタート眼球光学モデルデータベースには、縦軸に年令区分、横軸に概算レンズ度数区分が設けられ、それぞれの区分の遠点側の調節限界での値の眼球光学モデルと、年齢に応じた調節力があると仮定した近点側の調節限界での値の眼球光学モデルがあらかじめ作成されている。したがって、縦軸をＭ区分、横軸をＮ区分とすると、２×Ｍ×Ｎ個のスタート眼球光学モデルが記録され管理されている。なお、眼球光学モデルには、図１４に示すように、特願２００２−１２５０４９号に示されているものと同じものを適用する。
【００５４】
網膜上長さ算出手段３４は、被検査者が正円形の視標の長さが最も長く視認された方向に２つの視標を視認したときの中心点間距離Ｄ１、Ｄ２から、被検査者の眼球光学モデルの網膜上に写される視標の長さｄ１、ｄ２を算出する機能を有する。網膜上長さ算出手段３４は、画面から眼球光学モデルの水晶体前面までの距離Ｌ、眼球光学モデルの水晶体前面から網膜までの距離ｌ、中心点間距離Ｄ（Ｄ１またはＤ２）、および眼球光学モデルの網膜上の長さｄの関係が、図１５に示すように、式３で表されることより、式４により視標の長さｄ１およびｄ２を算出する。
【００５５】
【式３】

【００５６】
【式４】

【００５７】
なお、式３および式４のｌについては、眼球光学モデル決定手段３２が決定した眼球光学モデルの光学諸元からｌの値を決定し、Ｌについては、新聞紙の縦または横の長さと眼球光学モデル決定手段３２が決定した眼球光学モデルの光学諸元から算出する。
【００５８】
網膜上長さ補正手段３６は、有限の長さを有する視標を視認した場合に網膜上に結像される視標の長さｄ１、ｄ２から、視標が点の視標と仮定した場合の網膜上に結像される視標の長さｄ１´、ｄ２´を算出する。網膜上長さ補正手段３６は、画面に表示された視標が点と仮定した場合の網膜上の視標の長さの減少量ａ１、ａ２が式５で表されることより、式６により視標が点視標と仮定した場合の網膜上に結像される視標の長さｄ１´、ｄ２´を算出する。
【００５９】
【式５】

【００６０】
【式６】

【００６１】
なお、式５において、Ａは、表示装置での視標の長さ（ｍｍ）、式５および式６において、ａは、視標を点と仮定した場合の網膜上での長さの減少量の半分の値とする。なお、ｌ、Ｌについては、式３、式４で用いた値を用いる。
【００６２】
上述した眼球光学モデル決定手段３２は、視標が点の視標と仮定した場合の網膜上に結像される視標の長さｄ１´、ｄ２´に基づいて被検査者の眼球のピント位置、たとえば、近視の場合は網膜より前方にピント位置があり、遠視の場合は網膜より後方にピント位置があると仮定して、光学系自動設計処理を行って光学諸元を変化させ、点の視標が網膜上に長さｄ１´、ｄ２´に結像される眼球光学モデル（光学諸元）を決定する。なお、眼球光学モデルの構築には、特願２００２−１２５０４９号に記載した光学自動計算と同じ手法により行う。
【００６３】
被検査者端末５０は、検眼サーバ１２と種々のデータを送受信することにより視力測定を行うための端末である。被検査者端末５０としては、被検査者の自宅等に設置されている、パソコン、ワークステーション等のコンピュータが使用される。被検査者端末５０には、検眼サーバ１２と同様に、図示しないモデムやネットワークインターフェイスカードが装着されており、ネットワーク１００を介して、検眼サーバ１２とデータの送受信が行えるように構成されている。
【００６４】
被検査者端末５０には、ＷＷＷブラウザ（図示せず）が搭載されている。被検査者は、ＷＷＷブラウザのＵＲＬ入力欄に検眼サーバ１２に割当てられているＩＰアドレスやＵＲＬを入力することで、ＷＷＷサーバ１６にアクセスが可能である。ＷＷＷブラウザ内には、ＷＷＷサーバ１６から送信された視標データ２２に基づいて視標などの画像が表示され、被検査者の眼球の乱視軸、球面度数および乱視度数に関連するパラメータの測定が行われる。
【００６５】
ネットワーク１００には、インターネット回線が使用される。なお、この実施形態においては、ネットワーク１００にインターネット回線を使用したが、双方向のデータ通信が可能な回線であればよく、公衆回線網、ＩＳＤＮ回線網、携帯電話回線網、専用回線など使用されてもよい。
【００６６】
以下、本実施形態における動作について図１６を用いて説明する。
【００６７】
まず、被検査者端末５０のＷＷＷブラウザにＵＲＬが入力されることにより、被検査者端末５０と検眼サーバ１２との接続が行われる（ステップＳ１）。
【００６８】
被検査者端末５０から接続された検眼サーバ１２は、ＷＷＷサーバ１６を介して、被検査者端末５０の表示装置のサイズ、画面解像度や被検査者の年齢、性別などのデータを入力するフォームが表示されるＨＴＭＬデータを被検査者端末５０に送信する（ステップＳ２）。
【００６９】
表示装置のスペックを入力するフォームが表示されるＨＴＭＬデータを受信した被検査者端末５０の表示装置には、表示装置のスペックや被検査者の年齢等を問合せるフォームが表示される。被検査者は、自分の使用する被検査者端末５０の表示装置のスペックや年齢を適宜、マウスやキーボードを使用して、フォーム内に入力する。入力を終えた後、被検査者はフォーム内の設けられている「送信」ボタンをクリックすることにより、入力されたデータはＨＴＭＬデータとして検眼サーバ１２に送信する（ステップＳ３）。
【００７０】
送信されたＨＴＭＬデータを受信したＷＷＷサーバ１６は、ＣＧＩ１８にデータを引き渡す。ＣＧＩ１８は、被検査者により入力されたデータを抽出し、データの内容に基づいて、被検査者端末５０の表示装置に対応した視標データ２２をＨＴＭＬデータに組み入れて被検査者端末５０に送信する（ステップＳ４）。
【００７１】
視標データ２２を受信した被検査者端末５０の画面には、図２に示すように、視標２４ａおよび視標２４ｂが表示される。被検査者は、眼の遠点側の調節限界より視標が遠いために、指標がぼやけた状態で視認されるように、新聞紙を縦または横方向に丸めて作った筒の開口部を表示装置と眼の周辺部分に密着させた状態で、視標２４ａおよび視標２４ｂを見る。そして、被検査者は、図９に示すように、視標２４ａや視標２４ｂを見て最も長く視認した方向に視標２４ａと視標２４ｂとが配置されるように、キーボードの"←"キーと"→"キーを使って視標を回転させる。（ステップＳ５）。なお、視標２４ａが正円形に視認できる場合や、視標が最も長く視認した方向がわからない場合には、視標は回転させない。
【００７２】
被検査者は、ステップＳ５で視標２４ａと視標２４ｂとが配置した方向を変更しないで、図１０のように視標２４ａと視標２４ｂとが、視認上、外接するように、キーボードの"↑"キーと"↓"キーを使って視標を移動させる（ステップＳ６）。
【００７３】
視標２４ａ、２４ｂの位置を調整した後、被検査者は画面中の適宜な箇所に設けられた"送信"ボタンをクリックすることで、視標２４ａと視標２４ｂとが配置された視標の中心座標に関するデータをＨＴＭＬデータとして、ＷＷＷサーバ１６に送信する（ステップＳ７）。
【００７４】
２つの視標の中心座標に関するデータを受信した検眼サーバ１２は、式１および式２を用いて、乱視軸と直交する方向の角度である、被検査者が視標を最も長く視認した方向の角度θと、角度θ方向における被検査者が視認した視標の長さである、中心点間距離Ｄ１を算出する（ステップＳ８）。
【００７５】
角度θと中心点間距離Ｄ１を算出した後、検眼サーバ１２は、被検査者端末５０に角度θの値を記録したデータを送信する（ステップＳ９）。
【００７６】
角度θの値を記録したデータを受信した被検査者端末５０においては、視標２４ａと視標２４ｂとが角度θに直交する方向に配置された状態に表示される。このとき、視標２４ａと視標２４ｂとは、角度θに直交する方向にのみ移動可能に表示される（ステップＳ１０）。
【００７７】
被検査者は、図１２に示すように、視標２４ａと視標２４ｂとが、視認上、外接するように、キーボードの"↑"キーと"↓"キーを使って視標を移動させる（ステップＳ１１）。
【００７８】
視標２４ａ、２４ｂの位置を調整した後、被検査者は画面中の適宜な箇所に設けられた"送信"ボタンをクリックすることで、視標２４ａと視標２４ｂとが配置された視標の中心座標に関するデータをＨＴＭＬデータとして、ＷＷＷサーバ１６に送信する（ステップＳ１２）。
【００７９】
２つの視標の中心座標に関するデータを受信した検眼サーバ１２は、式１および式２を用いて、乱視軸方向の角度である、被検査者が視標を最も長く視認した角度θの方向と直交する角度と、その方向における被検査者が視認した視標の長さである、中心点間距離Ｄ２を算出する。なお、このとき、中心点間距離Ｄ１と中心点間距離Ｄ２との長さが等しく、ステップＳ５で視標が回転させられなかった場合は、乱視成分を有さず、被検査者が乱視でないと判断する（ステップＳ１３）。
【００８０】
検眼サーバ１２は、中心点間距離Ｄ１およびＤ２から、遠点側での眼球光学モデルの網膜上での視標の長さｄ１およびｄ２を算出する（ステップＳ１４）。
【００８１】
次に、被検査者は、眼の近点側の調節限界より視標が近いために、指標がぼやけた状態で視認される状態で、ステップＳ５からステップＳ１４を行い、近点側での眼球光学モデルの網膜上での視標の長さｄ１およびｄ２を算出する。このとき、被検査者は、眼の近点側の調節限界より視標が近くなるように、新聞紙の筒の変わりに、官製はがきを縦または横方向に丸めた筒を使用する（ステップＳ１５）。
【００８２】
遠点側、近点側での眼球光学モデルの網膜上での視標の長さｄ１およびｄ２を算出した検眼サーバ１２は、網膜上長さ算出手段３４により、視標が点の視標と仮定した場合の網膜上に結像される視標の長さｄ１'、ｄ２'を遠点側、近点側それぞれについて算出する（ステップＳ１６）。
【００８３】
検眼サーバ１２は、眼球光学モデル決定手段３２により、視標が点の視標と仮定した場合の網膜上に結像される遠点側の視標の長さｄ１'、ｄ２'および近点側の視標の長さｄ１'、ｄ２'に基づいて、被検査者の眼球のピントの位置を仮定して、眼球光学モデル（光学諸元）を決定する（ステップＳ１７）。
【００８４】
検眼サーバ１２において、眼鏡やコンタクトレンズの度数を決定するサービスを提供する場合には、特願２００２−１２５０４９号に示された同様の手順により眼鏡やコンタクトレンズの度数を決定する（ステップＳ１８）。なお、上述の実施形態では、片眼のみ検眼する場合について説明を行ったが、両眼について検眼を行う場合には、検眼していない眼の方を用いて、再度、ステップＳ５からステップＳ１８までの作業が行われる。
【００８５】
上述のように、この実施形態では、被検査者の主観や測定環境の影響を受けることなく、自覚的方法により乱視軸、眼球の球面度数、乱視度数を測定して精度の高い検眼が行える。特に、強度の近視や強度の乱視の被検査者に場合には、被検査者の眼球の光学特性に基づいて、視認する視標の形状に明瞭な変化が現れるので、測定誤差を少なく測定することができる。
【００８６】
なお、上述の実施形態においては、新聞紙と官製はがきの筒を使用して視標を見るようにしたが、これに限らず、Ｂ４紙、Ａ４紙、Ｂ５紙などのように、見るときに使用した紙の規格上の名称を特定することで、その紙のサイズを特定することができる紙などが使用されればよい。なお、この実施形態においては、被検査者の眼に入る表示手段以外からの光を遮断するために、新聞紙や官製はがきの筒を使用したが、これに限らず、室内を真っ暗にした状態などのように、外光や室内光が眼に入らないような状態で検眼するように構成されてもよい。
【００８７】
また、上述の実施形態では、視標に正円形の図形を使用したが、これに限らず、乱視軸を測定可能と設定した角度の刻みにおいて、視標の中心から輪郭までの長さが等しい、例えば、乱視軸を測定可能と設定した角度の刻み部分に突起設けた星形や、乱視軸を測定可能と設定した角度の刻み部分に頂点が設けられた正多角形などが視標に使用されてもよい。また、被検査者が最も変形して視認した方向において視認している視標の長さを測定するときは、正円形、星形、正多角形などの視標に限られることなく、長さを測定する方向における表示手段上での長さがわかる視標が使用されればよい。なお、長さを測定するときに使用する視標には、被検査者が外接させる部分を線として捉えるがことができるように、外接する部分に長さを測定する方向と直交する方向に幅広く端辺を設けてもよい。
【００８８】
なお、上述の実施形態では、被検査者の視力にかかわらず、所定の大きさの視標を用いて測定するように構成したが、この場合には、視標を視認させたときに視標がボケすぎて輪郭が判断できない場合があるので、あらかじめ視力測定表などを用いて簡易に視力を求めて、その視力に基づいて、使用する視標の大きさを変化させるように構成されてもよい。
【００８９】
また、上述の実施形態では、正円形の視標２４ａ,２４ｂを２つ用いて測定するように構成したが、これに限らず、２つ以上の視標を用いて測定するように構成されてもよい。例えば、図１７に示すように、視標２４ａ,２４ｂと同形・同色の視標を、点Ｐに固定表示して測定してもよいし、図１８に示すように、視標２４ａ,２４ｂと同形・同色で同じように移動する２つ視標を、視標２４ａ,２４ｂの内側に配置して測定してもよい。これらの場合には、視認した視標の変形が少ない、軽度の近視、軽度の遠視、軽度の乱視のときでも、被検査者が視標が変形した方向を認識しやすくなる。
【００９０】
さらに、上述の実施形態では、式６により、視標が点視標と仮定した場合の網膜上に結像される視標の長さを算出するように構成したが、これに限らず、多数の被検者のデータでメンバーシップ関数や推論ルールを構築し、ファジー推論を用いて長さを求めるようにしてもよい。また、多数の被検者のデータから網膜上の視標の長さと視標が点視標と仮定した場合の網膜上に結像される視標の長さとの関係を近点距離や被検者の属性をパラメータとした近似式を求め、それを用いて視標が点視標と仮定した場合の網膜上に結像される視標の長さを演算するようにしてもよい。さらに、中心点間距離Ｄ１、Ｄ２のみを用いて、被検査者の年齢などの属性から網膜上に結像される視標の長さを演算するようにしてもよい。また、簡易的ではあるが、目から画面までの距離をある一定距離に保った多数の被検査者の測定データから、画面上の乱視軸方向の視標の長さ、および乱視軸に直交する方向の視標の長さと、被検査者の属性（年齢、オートレフラクトメータによる測定値、必要によっては購入レンズ度数も含めて）との相関関係を導き出し、球面度数、乱視度数を推定してもよい。
【００９１】
上述の実施形態においては、検眼サーバ１２において、乱視軸と直交する方向の角度θ、中心点間距離Ｄ１やＤ２を算出するように構成したが、これに限らず、アプレットである視標データ２２によりこれらの値を算出し、その結果を検眼サーバ１２に送信するように構成されてもよい。
【００９２】
また、上述の実施形態においては、ＪＡＶＡのアプレットにより視標データ２２を作成したが、これに限らず、その他、Ｃ＃等の開発言語により作成されたアプリケーション、各種のスクリプトや、サーブレットなどのサーバサイドアプリケーションなどにより視標データが提供されてもよい。さらに、上述の実施形態においては、検眼サーバ１２から、視標データ２２などのデータを入手して検眼を行うように構成したが、これに限らず、上述したフローにより、被検査者端末５０のみ処理で検眼を行うようにプログラムされたアプリケーションをダウンロードして実行されるようにされてもよい。なお、前述したアプリケーションは、検眼サーバ１２からダウンロードさせるだけでなく、ＣＤ−ＲＯＭ等の頒布可能な記録媒体により提供されてもよい。
【００９３】
さらに、上述の実施形態のおいては、視標が最も長く視認された方向と、それに直交する方向との２つの方向についてのみ、視認上の視標を長さを測定するように構成したが、これに限らず、例えば、視標が最も長く視認された方向を基準に、３０度や４５度のなどの任意の刻みで、複数の方向について視認上の視標の長さを測定するように構成されてもよい。この場合には、被検査者が不正乱視であるかなど、さらに詳細に被検査者の眼球の光学特性を測定することができる。
【００９４】
上述の実施形態においては、被検査者が前記視標を最も変形して視認した方向として、視標が最も長く視認された方向に基づいて、検眼を行うように構成したが、これに限らず、視標が最も短く視認された方向に基づいて検眼するように構成されてもよい。
【００９５】
また、上述の実施形態においては、被検査者が前記視標を最も変形して視認した方向として、視標が最も長く視認された方向や、それに直交する方向に基づいて、検眼を行うように構成したが、これに限らず、あらかじめ設定した任意の刻みの角度において、視標の長さを測定し、被検査者が視標を視認している形状に関する情報を取得するように構成されてもよい。なお、この場合の角度の刻みは、被検査者が視標を視認している形状を図形として把握できるように、細かく設定されるのが好ましい。
【００９６】
上述の実施形態においては、視標データ２２のみ用いて、乱視軸、度数および乱視度数の測定を行ったが、これに限らず、乱視軸の測定を、図１９に示すような、視標データ２２ａを用いて測定してもよい。
【００９７】
視標データ２２ａは、図１９に示すように、最初に画面に表示されたとき、左側の縦方向略中央に白色で正円形の視標２４ｃと、右側の縦方向力中央に白色で直線状の視標２４ｄが垂直に表示される視標データである。視標データ２２ａの背景色には、視標が明瞭に視認できるように、黒色が使用してある。視標データ２２ａは、アプレットにより作成されており、被検査者端末５０のキーボード操作により直線状の視標２４ｄが回転自在に構成されている。
【００９８】
被検査者は、画面に表示された正円形の視標２４ｃと直線状の視標２４ｄとを、上述した実施形態と同様に、新聞紙の筒を用いて見る。被検査者は、図２０に示すように、視標を最も変形して視認した方向、この実施形態では正円形の視標２４ｃの長さが最も長く視認された方向に、直線状の視標２４ｄが平行となるように、直線状の視標２４ｄを回転させる。直線状の視標２４ｄが配置された方向は、乱視軸と直交する方向に配置されるので、直線状の視標２４ｂが何度に配置されているかをアプレットから取得することにより、被検査者の乱視軸を決定するためのパラメータとして、被検査者が視認している視標が最も長く視認された方向を取得することができる。
【００９９】
また、この実施形態においては、眼球の調節限界を超えた近点側および遠点側双方の位置において測定を行ったが、被検査者が遠視や老視などのように、近点側のみを調節する必要がある場合には、近点側の調節限界を超えた位置において測定した結果のみに基づいて眼球光学モデルを構築してもよい。なお、この場合には、本発明による測定を行う前に、被検査者に前回測定した測定結果を入力させたり、視力検査表を用いた簡易な測定を行うことにより、予め被検査者が遠視または老視であることを把握していることが必要である。
【０１００】
【発明の効果】
この発明によれば、安価で、被検査者の主観や測定環境の影響を受けることなく、近視、遠視、老視、乱視を精度良く測定することができ、特に、強度の近視、強度の遠視、強度の乱視にも対応可能な検眼システムおよび検眼プログラムを提供する。
【図面の簡単な説明】
【図１】この発明の一実施形態における検眼システムを示す図解図である。
【図２】視標データが表示された状態を示す図である。
【図３】視標データを示す図解図である。
【図４】視標データを示す別の図解図である。
【図５】直乱視の被検査者が正円形の視標を見たときに視認する映像を示す図である。
【図６】斜乱視の被検査者が正円形の視標を見たときに視認する映像を示す図である。
【図７】弱い近視の被検査者が正円形の視標を見たときに視認する映像を示す図である。
【図８】強い近視の被検査者が正円形の視標を見たときに視認する映像を示す図である。
【図９】視標２４ａおよび視標２４ｂを視標の長さが最も長く視認された方向に配置した状態を示す図解図である。
【図１０】視標２４ａと視標２４ｂとを外接させた状態を示す図解図である。
【図１１】視標２４ａおよび視標２４ｂを視標の長さが最も長く視認された方向と直交する配置した状態を示す図解図である。
【図１２】視標２４ａと視標２４ｂとを外接させた状態を示す別の図解図である。
【図１３】被検査者により視標の長さが最も長く視認された方向に配置された２つの視標の中心座標を示す図解図である。
【図１４】眼球光学モデルを示す図解図である。
【図１５】画面から眼球光学モデルの水晶体前面までの距離Ｌ、眼球光学モデルの水晶体前面から網膜までの距離ｌ、中心点間距離Ｄおよび眼球光学モデルの網膜上の長さｄの関係を示す図解図である。
【図１６】本実施形態における検眼システムの動作の示すフローチャート図である。
【図１７】３つの視標を用いて測定する場合の視標データが表示された状態を示す図である。
【図１８】４つの視標を用いて測定する場合の視標データが表示された状態を示す図である。
【図１９】乱視軸を測定する別の視標データを表示した状態を示す図である。
【図２０】直線状の視標を正円形の視標が最も長く視認された方向と並行となるように配置させたときを示す図である。
【図２１】視力表を示す図解図である。
【図２２】乱視軸測定チャートを示す図解図である。
【符号の説明】
１０ 検眼システム
１２ 検眼サーバ
１４ 中央処理部
１６ ＷＷＷサーバ
２０ 記憶領域
２２，２２ａ 視標データ
２４ａ，２４ｂ，２４ｃ，２４ｄ 視標
２６ 検眼機能部
２８ 眼球光学パラメータ決定手段
３０ 概算レンズ度数決定手段
３２ 眼球光学モデル決定手段
３４ 網膜上長さ算出手段
３６ 網膜上長さ補正手段
５０ 被検査者端末
１００ ネットワーク[0001]
BACKGROUND OF THE INVENTION
  This inventionOptometry system and optometry programIn particular, the computer can be used to calculate the astigmatism axis, spherical power, and astigmatism power values of the eyeball so that the eye can be accurately examined.Optometry system and optometry programAbout.
[0002]
[Prior art]
Conventionally, in order to measure visual acuity, an eye examination is performed by an objective examination method or a subjective examination method by directly going to an ophthalmologist or an eyeglass dealer and instructing an examiner. As an objective examination method, a method is generally used in which an eye refractometer is objectively measured using an autorefractometer, and the visual acuity is confirmed by wearing a correction lens actually provided. . In addition, as a subjective examination method, an eye test table on which symbols and characters such as Landolt's rings are displayed is used. Generally, a method of answering whether such a symbol or character is used, and the examiner determining the visual acuity from the answer result is common.
[0003]
In recent years, as a result of the dramatic expansion of the Internet environment in general households, the person undergoing the examination does not go directly to an ophthalmologist or a spectacles store, but performs an optometry at home, with glasses and contact lenses. Is expected to be able to buy. However, of course, in order to perform optometry at home, since there is no optometry device such as an autorefractometer in the consumer home, objective visual acuity testing cannot be performed. Therefore, in order to measure visual acuity via a network such as the Internet, image data is transmitted so that the visual examination table as shown in FIG. 21 or FIG. An individual uses a table to measure and determine the power, astigmatism axis, and astigmatism power.
[0004]
[Problems to be solved by the invention]
However, since the autorefractometer is a very expensive device, it is expected to provide an optometric device that is inexpensive and has high measurement accuracy.
[0005]
When measuring using an eye test chart, the target line to be selected cannot be determined because the line of the target line overlaps when the examinee visually recognizes the target. In many cases, the wrong optotype is selected due to the illusion or subjectivity of the examinee, resulting in an erroneous optometry result. In particular, this problem occurs in the case of an inspected person with high myopia or high intensity astigmatism where the target is not clearly visible. When measuring the eyesight under the instructions of the examiner, even if the examinee selected the wrong target, it was possible to judge whether the wrong answer was made by judging from the process of the examinee's answer. When there is no inspector, it is impossible for a third party to determine whether the selection result is a correct result or an incorrect result.
[0006]
Further, in the measurement performed using the visual acuity test chart, the measurement accuracy is likely to be affected by the illumination conditions of the environment where the subject is wearing. Therefore, it has been difficult to accurately measure the visual acuity of all examinees.
[0007]
Furthermore, in the measurement performed using the visual acuity test chart, there is a limitation on the size of the target displayed on the screen, and thus it was not possible to measure hyperopia, intensity myopia, and intensity astigmatism. Even in the case of a measurable astigmatism power, since the astigmatism axis measurement chart as shown in FIG. 22 must be used for measurement, the astigmatism axis cannot be measured in detail, and as a result, precise optometry cannot be performed.
[0008]
  Therefore, the main object of the present invention is to be able to accurately measure myopia, hyperopia, presbyopia and astigmatism without being affected by the subjectivity and measurement environment of the examinee, and in particular, high myopia. , Strong hyperopia and strong astigmatismOptometry system and optometry programIs intended to provide.
[0018]
[Means for Solving the Problems]
  Claim 1The invention described in 1 is an optometry system for performing eye examination by allowing a subject to visually recognize a target with a single eye at a predetermined distance, and displaying the target with a predetermined shape on the display unit. Visual target data providing means for providing visual target data for displaying the visual target, visual shape acquisition means for acquiring information on a shape in which the examinee is viewing the visual target, and the examinee Eyeball optical parameter determining means for determining optical parameters of the eyeball based on information on the shape being viewed.The visual shape acquisition means includes a length of a visual target in which the inspected person is visually recognizing the visual target in a direction in which the inspected person has deformed the visual target most visually, and the inspected person The eyeball optical parameter determination unit has a visual length measuring unit that measures the length of the visual target in which the examinee is viewing the visual target in a direction orthogonal to the direction in which the visual target is most deformed and viewed. Is the length of the visual target in which the inspected person is viewing the visual target in the direction in which the inspected person has most deformed and viewed the visual target, and the inspected person most deforms the visual target. Power determining means for determining the spherical power and astigmatic power of the eyeball based on the length of the visual target in which the examinee is viewing the visual target in a direction orthogonal to the visually recognized direction., Optometry system.
[0021]
  Claim 2The target data providing means provides target data for displaying a plurality of targets whose display positions can be changed, the target having the same length from the center to the contour of the target. The direction measuring means obtains a direction by arranging a plurality of targets on the examinee in a direction in which the examinee has deformed and viewed the target most,Claim 1The optometry system described in 1.
[0022]
  Claim 3The target data providing means provides target data for displaying a linear target that is rotatable together with a target whose length from the center of the target to the contour is equal, and the direction measuring means is , To obtain the direction by arranging the target in a straight line so that the target having the same length from the center to the contour is parallel to the direction in which the target is most deformed and viewed;Claim 1 or claim 2The optometry system described in 1.
[0023]
  Claim 4The target data providing means displays the target data for displaying two targets of the same shape that are movable in the direction of measuring the length of the target on the direction of measuring the length of the target. The visual length measuring means obtains the center coordinates of the visual target when the visual target is arranged so as to be visually recognized when both or one of the visual targets is moved to the examinee and circumscribed. To calculate the length of the target,Claims 1 to 3The optometry system according to any one of the above.
[0024]
  Claim 5In the invention described in the above, the direction in which the inspected person visually deforms the visual target most is the direction in which the inspected person visually recognizes that the length of the visual target is the longest, or the length of the visual target is It is the direction visually recognized as short,Claims 1 to 4The optometry system according to any one of the above.
[0025]
  Claim 6The invention described in (2) has a distance holding unit that maintains a predetermined distance from the display unit to the eye of the subject.Claims 1 to 5The optometry system according to any one of the above.
[0026]
  Claim 7The invention described in (1) has a light shielding means for preventing light from other than the display means from entering the eye of the subject.Claims 1 to 6The optometry system according to any one of the above.
[0027]
  Claim 8According to the invention described in the above, the light-shielding hand for preventing the light from other than the display means from entering the eye of the examinee.StageThe cylindrical body has an opening portion that can be in close contact with the screen of the display means and the peripheral portion of the eye of the subject.Claim 7The optometry system described in 1.
The invention according to claim 9 is a step of causing the examinee to visually recognize the target displayed on the display means with one eye and displaying the target of a predetermined shape on the display means, and the examinee displays the target An optometry program that causes a computer to execute a step of acquiring information about a shape that is visually recognized and a step of determining optical parameters of an eyeball based on information about a shape that the examinee is viewing the target. The step of acquiring the information related to the shape of the inspected person visually recognizing the optotype is that the inspected person in the direction in which the inspected person visually deforms and visually recognizes the optotype visually recognizes the optotype. Measuring the length of the target that is being viewed, and a target that is being viewed by the subject in the direction orthogonal to the direction in which the subject is most deformed and viewing the target. Step to measure the length And determining the optical parameters of the eyeball based on information relating to the shape of the visual target being viewed by the inspected person, wherein the inspected person viewed the visual target most deformed The length of the target in which the examinee in the direction visually recognizes the target, and the subject in the direction perpendicular to the direction in which the subject inspected the target most deformed and viewed the target An optometry program including a step of determining a spherical power and an astigmatism power of an eyeball based on a length of a visual target being visually recognized.
[0028]
The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the drawings.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an illustrative view showing an optometry system in one embodiment of the present invention. As shown in FIG. 1, the optometry system 10 includes an optometry server 12, an inspected person terminal 50, and a network 100.
[0030]
The optometry server 12 provides the test subject terminal 50 with data such as optotype data, and measures the astigmatism axis, spherical power, and astigmatism axis of the subject's eye from the contents input and operated on the test subject terminal 50. And has a function of performing optometry. As the hardware of the optometry server 12, a computer such as a personal computer, a workstation, or a server is used. The optometry server 12 can provide various services by installing various applications. The optometry server 12 is equipped with a modem and a network interface card (not shown), and can transmit and receive data to and from the patient terminal 50 via the network 100.
[0031]
The optometry server 12 has a central processing unit 14. The central processing unit 14 controls and manages the operation of each means described later.
[0032]
The central processing unit 14 is connected to a WWW server 16 which is a target data providing unit. The WWW server 16 has a function of performing bidirectional communication with the inspected person terminal 50 via the network 100. The WWW server 16 transmits HTML data, image data, and various programs to the inspected person terminal 50 based on contents input / operated by an input means (not shown) such as a mouse or a keyboard of the inspected person terminal 50. . In addition, the WWW server 16 receives the data input and transmitted from the inspected person terminal 50.
[0033]
A CGI 18 is connected to the WWW server 16. The CGI 18 has a function of dynamically generating HTML data corresponding to the content of data transmitted from the inspected person terminal 50 and delivering the generated HTML data to the WWW server 16. The CGI 18 functions as a visual shape acquisition unit. The CGI 18 extracts data relating to the shape of the inspected person visually recognizing the visual target from the data delivered from the WWW server 16. The CGI 18 delivers the extracted / acquired data to the eyeball optical parameter determination means 28 described later.
[0034]
The target data 22 is stored in the storage area 20 from which the WWW server 16 reads various data. The optotype data 22 is appropriately transmitted to the inspected person terminal 50 as a part of HTML data and displayed on the display device of the inspected person terminal 50.
[0035]
Hereinafter, the target data 22 used in the present embodiment will be described. The target data 22 is data in which an image as shown in FIG. 2 is displayed on the display device. The optotype data 22 is generated as an applet of JAVA (registered trademark of Sun Microsystems). The target data 22 displays a white and circular target 24a and a target 24b having the same shape and color as the target 24a. Although it is impossible to display a perfect circular target due to the structure of display means such as the current CRT and liquid crystal display, a target that is visible as a circular shape when viewed by a person is displayed. It only has to be done. The background color of the target data 22 is black. Thereby, even if the examinee is visually recognizing the visual targets 24a and 24b, the visual targets 24a and 24b can be clearly recognized. When the target 24a and the target 24b are displayed for the first time, they are displayed side by side in the vertical direction in the center of the WWW browser of the inspected person terminal 50. As shown in FIG. 3, the optotype data 22 is arranged in a state where the optotype 24a, the optotype 24b, and the point P (not displayed on the screen) are arranged on a straight line. At this time, the target 24a and the target 24b are arranged symmetrically at the point P. The optotype 24a and the optotype 24b are configured such that the optotype 24a and the optotype 24b can rotate simultaneously while maintaining a symmetrical state at the point P. The target 24a and the target 24b are rotated by the subject using the “←” and “→” keys on the keyboard of the subject terminal 50.
[0036]
Further, as shown in FIG. 4, the optotype data 22 includes the optotype 24a and the optotype 24b in a state where the optotype 24a, the optotype 24b, and the point P (not displayed on the screen) are arranged on a straight line. Are configured to be movable so as to approach or leave the point P while maintaining a symmetrical state at the point P. The target 24a and the target 24b are moved by the subject using the “↑” key or the “↓” key on the keyboard.
[0037]
The optotype data 22 is information for obtaining a shape of the inspected person viewing the target as parameters for determining the astigmatic axis, spherical power, and astigmatic power of the inspected person. The examinee views the visual target 24a and the visual target 24b displayed on the screen using a newspaper newspaper rolled up vertically or horizontally into a cylindrical shape. At this time, the examinee presses the opening of the newspaper against the display device of the examinee terminal 50 and the periphery of one eye of the examinee to bring them into close contact. This is to block outside light so that light from other than the display device does not enter the eye of the subject. The examinee looks at the visual target 24a and the visual target 24b in the visual field while maintaining this state.
[0038]
When the inspected person has astigmatism, the targets 24a and 24b are deformed so as to extend in a direction perpendicular to the astigmatic axis of the inspected person instead of the regular circle as shown in FIG. The visual targets 24a and 24b are visually recognized as an ellipse, a triangle, a sector, a rectangle, and the like. For example, when the subject has direct astigmatism, as shown in FIG. 5, the right circular targets 24 a and 24 b are visually recognized as an elliptical shape extending in the vertical direction, and when the subject has oblique astigmatism. As shown in FIG. 6, regular circular targets 24a and 24b are visually recognized as elliptical shapes extending obliquely.
[0039]
When the examinee is myopic, the target is far from the adjustment limit on the far point side of the eye, so the targets 24a and 24b are not clearly circular as shown in FIG. Blurred and visible larger than actual size. For example, when the subject is light myopia, as shown in FIG. 7, the target is visually recognized slightly larger than the actual size, and when the subject is strong myopia, as shown in FIG. The target is viewed larger than the actual size.
[0040]
In order for the examinee to measure the astigmatism axis of the examinee, the target 24a and the target 24b are arranged in the direction in which the length of the target 24a and the target 24b is viewed the longest. The targets 24a and 24b are rotated. When the examinee visually recognizes the visual targets 24a and 24b as shown in FIG. 6, as shown in FIG. 9, the visual targets 24a and 24b are set in the same direction as the direction in which the length of the visual targets 24a and 24b is viewed the longest. And a visual target 24b. The straight line connecting the visual target 24a and the visual target 24b after being placed on the subject is arranged in a direction orthogonal to the astigmatic axis of the subject. As a result, by obtaining how many times the inclination of the straight line connecting the visual target 24a and the visual target 24b is arranged from the applet, the inspected person can visually recognize as a parameter for determining the astigmatic axis of the inspected person. The direction in which the target is viewed the longest can be acquired.
[0041]
In order to measure the spherical power and astigmatism power of the eyeball in the direction orthogonal to the astigmatism axis, the examinee, as shown in FIG. 10, has the target 24a and the target in the direction in which the target is viewed with the longest length. In the state where 24b is arranged, the visual targets 24a and 24b are moved so that the visual target 24a and the visual target 24b are circumscribed for visual recognition. The distance between the center points of the visual target 24a and the visual target 24b in a state where the visual target 24a and the visual target 24b are viewed as circumscribed is the direction in which the examinee visually recognizes the length of the visual targets 24a and 24b the longest. The value is equal to the length of each of the visual targets 24a and 24b visually recognized by the subject. As a result, the astigmatism axis of the eyeball of the examinee can be obtained by obtaining the distance between the center points of the visual target 24a and the visual target 24b in a state in which the examinee circumscribes the visual target 24a and the visual target 24b from the applet. As a parameter for determining the spherical power and the astigmatic power in the orthogonal direction, the length of the target visually recognized by the examinee in the direction in which the examinee visually recognizes the length of the visual targets 24a and 24b is the longest. You can get the value.
[0042]
After acquiring the direction in which the examinee has viewed the target for the longest time and the length in that direction, the target data 22 as shown in FIG. 11 is displayed. The target 24a and the target 24b are arranged so that a straight line connecting the target 24a, the point P, and the target 24b is orthogonal to the direction in which the subject has viewed the target for the longest time. The target 24a and the target 24b are movable so as to approach or leave the point P while maintaining a symmetrical state at the point P in the direction in which the target is viewed the longest. Note that the above-described target state is dynamically generated by the index data 22 that is an applet based on the direction in which the examinee has viewed the index the longest. The target 24a and the target 24b are moved by the subject using the “↑” key or the “↓” key on the keyboard.
[0043]
In order to measure the spherical power and astigmatism power of the eyeball in the astigmatism axis direction, the subject to be inspected visually in a direction perpendicular to the direction in which the length of the target is viewed the longest as shown in FIG. The target 24a and the visual target 24b are moved so as to circumscribe. The distance between the center points of the visual target 24a and the visual target 24b in a state where the visual target 24a and the visual target 24b are viewed as circumscribed is the direction in which the examinee visually recognizes the length of the visual targets 24a and 24b the longest. It is a value equal to the length of each of the visual targets 24a and 24b visually recognized by the examinee in the direction orthogonal to. As a result, the astigmatism axis direction of the eyeball of the examinee is obtained by obtaining from the applet the distance between the center points of the optotype 24a and the optotype 24b in a state where the examinee circumscribes the optotype 24a and the optotype 24b. As a parameter for determining the spherical power and the astigmatism power in, the value of the length of the visual target viewed by the examinee in the direction in which the subject visually recognizes the length of the visual targets 24a and 24b is obtained. Is possible.
[0044]
The target data 22 includes the display device type (CRT, liquid crystal), size (14 inches, 17 inches, etc.), screen resolution (width 800 × length 600, width 1024 × length 768, etc.). Since the size of the displayed target is different, a plurality of target data 22 having different target sizes and different image resolutions are stored so as to be displayed in a predetermined size on all display devices. Has been.
[0045]
An optometry function unit 26 is connected to the CGI 18. The optometry function unit 26 determines the approximate power of the subject based on the measurement result input and measured at the subject terminal 50, constructs an eyeball optical model, and selects glasses and contact lenses suitable for the examiner. Has a function to select. In order to realize the above-described functions, the optometry function unit 26 includes an eyeball optical parameter determination unit 28, an approximate lens power determination unit 30, an eyeball optical model determination unit 32, an upper retina length calculation unit 34, and an upper retina length correction unit. 36.
[0046]
Based on the information acquired from the target data 22, the eyeball optical parameter determination unit 28 determines the target visually recognized in the astigmatic axis of the subject, the astigmatic axis direction of the subject, and the direction orthogonal to the astigmatic axis. Has the function of determining the length value
[0047]
Specifically, the eyeball optical parameter determination unit 28 acquires the values of the center coordinates of the visual targets 24a and 24b that the CGI 18 acquires from the applet and is visually recognized by the examinee. As shown in FIG. 13, the eyeball optical parameter determination means 28 is configured such that the central coordinates of the visual targets 24 a and 24 b arranged in the direction in which the visual targets 24 a and 24 b are viewed by the examinee are the longest (Xa , Ya), (Xb, Yb), the angle θ in the direction orthogonal to the astigmatism axis is calculated by Equation 1.
[0048]
[Formula 1]

[0049]
Further, the eyeball optical parameter determination means 28 calculates the distance D1 between the center points of the visual targets 24a and 24b arranged in the direction in which the length of the regular circular visual target 24a is viewed by the subject as the longest, according to the equation (2). The length of the visual target viewed by the examinee in the direction in which the visual target is viewed the longest) is calculated.
[0050]
[Formula 2]

[0051]
The eyeball optical parameter determination means 28 is the center of the targets 24a and 24b arranged in a direction (astigmatic axis) perpendicular to the direction θ in which the length of the right circular target 24a is viewed by the examinee. The point-to-point distance D2 (the length of the target visually recognized by the examinee in the direction orthogonal to the direction in which the target is viewed the longest) is also calculated by inputting the center coordinates in Equation 2.
[0052]
The approximate lens power determination means 30 has a function of determining the approximate lens power of the subject based on the distance D1 between the center points of the target calculated by the eyeball optical parameter determination means 28 and the distance D2 between the center points. The approximate lens power determination means 30 approximates the lens power of the examinee from the distance between the center points of the visual target based on the data collected about the relationship between the distance between the central points of the visual target and the lens power of the examinee. The table for storing is stored. The approximate lens power determination means 30 approximates the lens power of the subject in the astigmatism axis direction and the direction orthogonal to the astigmatism axis based on the center point distance D1 and the center point distance D2.
[0053]
The eyeball optical model determining means 32 is configured to select the start eyeball model from the age classification and the approximate lens power as the start eyeball model. Note that the start eyeball optical model is a model in which the vertical axis is provided with age divisions and the horizontal axis is provided with approximate lens power divisions, and an eyeball optical model at the median value of each division is created in advance. In this embodiment, the eyeball optical model determining means 32 is configured to be able to determine a start eyeball optical model as an initial value based on the age of the examinee and the approximate lens power. The eyeball optical model determining means 32 stores a start eyeball optical model database (not shown). The start eye optical model database has age categories on the vertical axis and approximate lens power categories on the horizontal axis. The eye optics model of the values at the far-end adjustment limit of each category and the adjustment according to the age An eyeball optical model of a value at the adjustment limit on the near point side assuming that there is a force is created in advance. Therefore, if the vertical axis is M section and the horizontal axis is N section, 2 × M × N start eye optical models are recorded and managed. In addition, as shown in FIG. 14, the same eyeball optical model as that shown in Japanese Patent Application No. 2002-125049 is applied.
[0054]
The upper retina length calculation means 34 calculates the distance between the center points D1 and D2 when the subject visually recognizes two targets in the direction in which the length of the perfect circular target is viewed the longest. The eyeball optical model has a function of calculating the lengths d1 and d2 of the visual target imaged on the retina. The retina length calculation means 34 includes a distance L from the screen to the lens front surface of the eyeball optical model, a distance l from the lens front surface of the eyeball optical model to the retina, a center point distance D (D1 or D2), and an eyeball optical model. As shown in FIG. 15, the relationship between the length d on the retina is expressed by Expression 3, and the lengths d1 and d2 of the visual target are calculated by Expression 4.
[0055]
[Formula 3]

[0056]
[Formula 4]

[0057]
For l in Equations 3 and 4, the value of l is determined from the optical specifications of the eyeball optical model determined by the eyeball optical model determining means 32. For L, the vertical or horizontal length of the newspaper and the eyeball optics are determined. It is calculated from the optical specifications of the eyeball optical model determined by the model determining means 32.
[0058]
The retina length correction means 36 assumes that the visual target is a point visual target from the lengths d1 and d2 of the visual target formed on the retina when a visual target having a finite length is visually recognized. The lengths d1 'and d2' of the target imaged on the retina are calculated. The on-retina length correction means 36 uses the expression 6 to express the reduction amounts a1 and a2 of the length of the target on the retina when the target displayed on the screen is a point. When the target is assumed to be a point target, the lengths d1 ′ and d2 ′ of the target imaged on the retina are calculated.
[0059]
[Formula 5]

[0060]
[Formula 6]

[0061]
In Equation 5, A is the length (mm) of the target on the display device, and in Equations 5 and 6, a is the amount of decrease in length on the retina when the target is assumed to be a point. Half of the value. For l and L, the values used in equations 3 and 4 are used.
[0062]
The eyeball optical model determining means 32 described above is based on the lengths d1 ′ and d2 ′ of the target imaged on the retina when the target is assumed to be a point target. For example, assuming that the focus position is ahead of the retina for myopia and the focus position is behind the retina for hyperopia, an optical system automatic design process is performed to change the optical specifications. An eyeball optical model (optical specifications) in which the visual target is imaged on the retina to the lengths d1 ′ and d2 ′ is determined. The eyeball optical model is constructed by the same technique as the automatic optical calculation described in Japanese Patent Application No. 2002-125049.
[0063]
The inspected person terminal 50 is a terminal for performing visual acuity measurement by transmitting and receiving various data to and from the optometry server 12. As the inspected person terminal 50, a computer such as a personal computer or a workstation installed in the inspected person's home or the like is used. Similarly to the optometry server 12, the inspected person terminal 50 is equipped with a modem and a network interface card (not shown), and is configured to transmit and receive data to and from the optometry server 12 via the network 100.
[0064]
The inspected person terminal 50 is equipped with a WWW browser (not shown). The examinee can access the WWW server 16 by inputting the IP address or URL assigned to the optometry server 12 in the URL input field of the WWW browser. In the WWW browser, an image such as a visual target is displayed based on the visual target data 22 transmitted from the WWW server 16, and parameters relating to the astigmatic axis, spherical power, and astigmatic power of the eyeball of the examinee are measured. Done.
[0065]
The network 100 uses an internet line. In this embodiment, an Internet line is used for the network 100. However, any line capable of bidirectional data communication may be used, and a public line network, an ISDN line network, a mobile phone line network, a dedicated line, etc. are used. May be.
[0066]
Hereinafter, the operation in the present embodiment will be described with reference to FIG.
[0067]
First, the URL is input to the WWW browser of the inspected person terminal 50, whereby the inspected person terminal 50 and the optometry server 12 are connected (step S1).
[0068]
The optometry server 12 connected from the inspected person terminal 50 has a form for inputting data such as the size of the display device of the inspected person terminal 50, the screen resolution, the age of the inspected person, and the gender via the WWW server 16. The displayed HTML data is transmitted to the inspected person terminal 50 (step S2).
[0069]
A form for inquiring about the specifications of the display device, the age of the examinee, and the like is displayed on the display device of the inspected person terminal 50 that has received the HTML data on which the form for inputting the specifications of the display apparatus is displayed. The examinee inputs the specifications and age of the display device of the examinee terminal 50 used by the examinee into the form using a mouse or a keyboard as appropriate. After completing the input, the examinee clicks a “send” button provided in the form, and the input data is transmitted to the optometry server 12 as HTML data (step S3).
[0070]
The WWW server 16 that has received the transmitted HTML data delivers the data to the CGI 18. The CGI 18 extracts data input by the inspected person, and incorporates the target data 22 corresponding to the display device of the inspected person terminal 50 into the HTML data based on the contents of the data and transmits it to the inspected person terminal 50. (Step S4).
[0071]
As shown in FIG. 2, a target 24 a and a target 24 b are displayed on the screen of the inspected person terminal 50 that has received the target data 22. The examinee displays the opening of the tube made by rolling newspaper in the vertical or horizontal direction so that the target is farther than the adjustment limit on the far point side of the eye, so that the indicator is visually blurred. The visual target 24a and the visual target 24b are viewed in a state of being in close contact with the peripheral portion of the apparatus and the eye. Then, as shown in FIG. 9, the examinee places “←” on the keyboard so that the visual target 24 a and the visual target 24 b are arranged in the direction in which the visual target 24 a and the visual target 24 b are viewed the longest. Use the key and "→" key to rotate the target. (Step S5). In addition, when the visual target 24a can be visually recognized as a perfect circle, or when the direction in which the visual target is viewed the longest is not known, the visual target is not rotated.
[0072]
The examinee does not change the direction in which the visual target 24a and the visual target 24b are arranged in step S5, and the visual target 24a and the visual target 24b are visually circumscribed as shown in FIG. The target is moved using the “↑” key and the “↓” key (step S6).
[0073]
After adjusting the positions of the visual targets 24a and 24b, the examinee clicks a “send” button provided at an appropriate location on the screen, so that the visual targets 24a and 24b are arranged. Is transmitted to the WWW server 16 as HTML data (step S7).
[0074]
The optometry server 12 that has received the data relating to the center coordinates of the two targets uses the formulas 1 and 2 to determine the direction in which the subject has viewed the target for the longest time, which is the angle in the direction orthogonal to the astigmatism axis. The center point distance D1 that is the angle θ and the length of the visual target visually recognized by the subject in the angle θ direction is calculated (step S8).
[0075]
After calculating the angle θ and the center point distance D1, the optometry server 12 transmits data in which the value of the angle θ is recorded to the inspected person terminal 50 (step S9).
[0076]
In the subject terminal 50 that has received the data in which the value of the angle θ is recorded, the visual target 24a and the visual target 24b are displayed in a state where they are arranged in a direction orthogonal to the angle θ. At this time, the visual target 24a and the visual target 24b are displayed so as to be movable only in a direction orthogonal to the angle θ (step S10).
[0077]
As shown in FIG. 12, the examinee moves the target using the “↑” key and the “↓” key of the keyboard so that the target 24a and the target 24b are circumscribed for visual recognition ( Step S11).
[0078]
After adjusting the positions of the visual targets 24a and 24b, the examinee clicks a “send” button provided at an appropriate location on the screen, so that the visual targets 24a and 24b are arranged. Is transmitted to the WWW server 16 as HTML data (step S12).
[0079]
The optometry server 12 that has received data relating to the center coordinates of the two targets uses the formulas 1 and 2 to determine the direction of the angle θ at which the subject has viewed the target for the longest time, which is the angle in the astigmatic axis direction. A center-to-center distance D2 which is an orthogonal angle and the length of the visual target visually recognized by the subject in that direction is calculated. At this time, when the distance between the center points D1 and the distance between the center points D2 is equal and the target is not rotated in step S5, there is no astigmatism component and the subject is not astigmatism. Is determined (step S13).
[0080]
The optometry server 12 calculates the lengths d1 and d2 of the visual target on the retina of the eyeball optical model on the far point side from the distances D1 and D2 between the center points (step S14).
[0081]
Next, since the visual target is closer than the adjustment limit on the near point side of the eye, the examinee performs steps S5 to S14 in a state where the index is visually recognized in a blurred state, and the eyeball on the near point side The lengths d1 and d2 of the visual target on the retina of the optical model are calculated. At this time, the examinee uses a cylinder in which government-made postcards are rounded in the vertical or horizontal direction instead of the newspaper cylinder so that the target is closer to the adjustment limit on the near point side of the eye (step S15). .
[0082]
The optometry server 12 that has calculated the lengths d1 and d2 of the visual target on the retina of the eyeball optical model on the far point side and the near point side is determined by the upper retina length calculating means 34 to determine whether the visual target is a point target. The lengths d1 ′ and d2 ′ of the target imaged on the retina when assumed are calculated for the far point side and the near point side, respectively (step S16).
[0083]
The optometry server 12 uses the eyeball optical model determination unit 32 to determine the lengths d1 ′ and d2 ′ of the far visual target imaged on the retina when the visual target is assumed to be a point visual target and the near point side. Based on the target lengths d1 ′ and d2 ′, the eyeball optical model (optical specifications) is determined assuming the focus position of the eyeball of the subject (step S17).
[0084]
When the optometry server 12 provides a service for determining the power of eyeglasses or contact lenses, the power of the eyeglasses or contact lenses is determined by the same procedure described in Japanese Patent Application No. 2002-125049 (step S18). In the above-described embodiment, the case where only one eye is examined has been described. However, in the case where both eyes are examined, steps S5 to S18 are performed again using an eye that has not been examined. Work is done.
[0085]
As described above, in this embodiment, a highly accurate optometry can be performed by measuring the astigmatism axis, the spherical power of the eyeball, and the astigmatism power by a subjective method without being affected by the subjectivity and measurement environment of the subject. In particular, in the case of an inspected person with high myopia or strong astigmatism, a clear change appears in the shape of the target to be viewed based on the optical characteristics of the eyeball of the inspected person. be able to.
[0086]
In the above embodiment, newspapers and government postcards are used to view the target. However, the present invention is not limited to this, and it is used when viewing, such as B4 paper, A4 paper, B5 paper, etc. It is only necessary to use a paper or the like that can specify the size of the paper by specifying the name in the standard of the paper. In this embodiment, newspaper or government postcard cylinders are used to block light from other than the display means that enters the eye of the examinee. However, the present invention is not limited to this. As described above, the optometry may be performed in a state in which outside light or room light does not enter the eye.
[0087]
In the above-described embodiment, a regular circular figure is used for the target. However, the present invention is not limited to this, and the length from the center of the target to the contour is the same in increments of angles at which the astigmatic axis can be measured. For example, a star with a protrusion provided at an angle step where the astigmatism axis can be measured, or a regular polygon with a vertex provided at an angle step where the astigmatism axis can be measured is used for the target. May be. In addition, when measuring the length of a target visually recognized in the direction in which the examinee is most deformed and visually recognized, the length is not limited to a target such as a regular circle, a star, or a regular polygon. It is only necessary to use a visual target whose length on the display means in the direction of measuring the distance is measured. It should be noted that the target used for measuring the length is wide in the direction perpendicular to the direction of measuring the length of the circumscribed part so that the part circumscribed by the examinee can be grasped as a line. An end side may be provided.
[0088]
In the above-described embodiment, the measurement is performed using a target having a predetermined size regardless of the visual acuity of the examinee. In this case, the target is viewed when the target is visually recognized. However, the outline may not be determined due to excessive blurring, so it is possible to easily obtain visual acuity using a visual acuity measurement table in advance and change the size of the target to be used based on the visual acuity. Good.
[0089]
Further, in the above-described embodiment, the measurement is performed by using the two circular targets 24a and 24b. However, the measurement is not limited thereto, and the measurement is performed by using two or more targets. Also good. For example, as shown in FIG. 17, a target having the same shape and color as the targets 24a and 24b may be fixedly displayed at the point P, and as shown in FIG. 18, the targets 24a and 24b may be measured. Two targets having the same shape and the same color and moving in the same way may be measured by placing them inside the targets 24a and 24b. In these cases, it is easy for the examinee to recognize the direction in which the visual target is deformed even in the case of mild myopia, mild hyperopia, or mild astigmatism, with little deformation of the visually recognized target.
[0090]
Further, in the above-described embodiment, the length of the target image formed on the retina when the target is assumed to be a point target is calculated by Equation 6, but the present invention is not limited to this. It is also possible to construct a membership function or an inference rule with the data of the subject and to obtain the length using fuzzy inference. In addition, the relationship between the length of the target on the retina and the length of the target imaged on the retina when the target is assumed to be a point target from the data of a large number of subjects is calculated. It is also possible to obtain an approximate expression using a person's attribute as a parameter and calculate the length of the target imaged on the retina when the target is assumed to be a point target. Furthermore, the length of the target imaged on the retina may be calculated from the attributes such as the age of the subject using only the center point distances D1 and D2. In addition, although it is simple, it is orthogonal to the astigmatism axis and the length of the target in the direction of the astigmatism axis on the screen, based on the measurement data of a large number of subjects who maintain a certain distance from the eyes to the screen. Deriving the correlation between the direction target length and the subject's attributes (age, measured by autorefractometer, including purchased lens power if necessary), and estimating spherical power and astigmatism power Good.
[0091]
In the above-described embodiment, the optometry server 12 is configured to calculate the angle θ in the direction orthogonal to the astigmatism axis and the distances D1 and D2 between the center points. May be configured to calculate these values and transmit the result to the optometry server 12.
[0092]
Further, in the above-described embodiment, the target data 22 is created by using an applet of JAVA. However, the present invention is not limited to this, and other applications created in a development language such as C #, various scripts, and servers such as servlets. The target data may be provided by a side application or the like. Furthermore, in the above-described embodiment, the configuration is such that data such as the optotype data 22 is obtained from the optometry server 12, and the optometry is performed. An application programmed to perform optometry in the process may be downloaded and executed. The application described above may be provided not only by downloading from the optometry server 12 but also by a recordable recording medium such as a CD-ROM.
[0093]
Furthermore, in the above-described embodiment, the visual target is configured to measure the length only in the two directions of the direction in which the visual target is viewed the longest and the direction orthogonal thereto. Not limited to this, for example, the visual target length is measured in a plurality of directions at an arbitrary interval such as 30 degrees or 45 degrees with respect to the direction in which the visual target is viewed the longest. May be configured. In this case, the optical characteristics of the eyeball of the subject can be measured in more detail, such as whether the subject has irregular astigmatism.
[0094]
In the above-described embodiment, the optometry is performed based on the direction in which the examinee has viewed the target most deformed and viewed as the direction in which the target is viewed the longest. However, the present invention is not limited thereto. The eye may be configured to be examined based on the direction in which the target is viewed shortest.
[0095]
Further, in the above-described embodiment, the optometry is performed based on the direction in which the inspected person has viewed the target most deformed and viewed as the direction in which the target has been viewed the longest or the direction orthogonal thereto. Although configured, the present invention is not limited to this, and is configured to measure the length of a target at an arbitrary angle set in advance, and to acquire information on the shape of the subject viewing the target. Also good. Note that the angle increment in this case is preferably set finely so that the shape of the inspected person viewing the target can be grasped as a figure.
[0096]
In the above-described embodiment, the astigmatism axis, the power, and the astigmatism power are measured using only the optotype data 22, but not limited to this, the astigmatism axis is measured as shown in FIG. You may measure using 22a.
[0097]
When the target data 22a is first displayed on the screen, as shown in FIG. 19, the target 24c is a white and circular shape at the approximate center of the left side in the vertical direction, and the white and straight target is at the center of the right side in the vertical direction. The visual target 24d is the visual target data displayed vertically. The background color of the target data 22a is black so that the target can be clearly seen. The optotype data 22a is created by an applet, and a linear optotype 24d is configured to be rotatable by a keyboard operation of the terminal 50 to be inspected.
[0098]
The examinee looks at the circular target 24c and the linear target 24d displayed on the screen using a newspaper tube as in the above-described embodiment. As shown in FIG. 20, the inspected person has a linear target in the direction in which the target is most deformed and viewed, that is, in the direction in which the length of the regular circular target 24c is viewed as the longest in this embodiment. The linear visual target 24d is rotated so that 24d becomes parallel. Since the direction in which the linear visual target 24d is arranged is arranged in a direction orthogonal to the astigmatic axis, by obtaining from the applet how many times the linear visual target 24b is arranged, the subject to be inspected can be obtained. As a parameter for determining the astigmatism axis, it is possible to obtain the direction in which the visual target viewed by the subject is viewed the longest.
[0099]
Further, in this embodiment, the measurement was performed at both the near point side and the far point side exceeding the eyeball adjustment limit, but only the near point side was examined by the subject such as hyperopia or presbyopia. When it is necessary to adjust, an eyeball optical model may be constructed based only on the result of measurement at a position exceeding the adjustment limit on the near point side. In this case, before performing the measurement according to the present invention, the inspected person is previously hyperopic by inputting the measurement result of the previous measurement to the inspected person or performing a simple measurement using the visual acuity test table. Or you need to know that you are presbyopic.
[0100]
【The invention's effect】
  According to the present invention, it is inexpensive and can accurately measure myopia, hyperopia, presbyopia, and astigmatism without being affected by the subjectivity and measurement environment of the examinee. Can handle intense astigmatismOptometry system and optometry programI will provide a.
[Brief description of the drawings]
FIG. 1 is an illustrative view showing an optometry system according to an embodiment of the present invention;
FIG. 2 is a diagram illustrating a state in which target data is displayed.
FIG. 3 is an illustrative view showing target data.
FIG. 4 is another illustrative view showing target data.
FIG. 5 is a diagram showing an image visually recognized when a subject with direct astigmatism sees a perfect circular target.
FIG. 6 is a diagram showing an image visually recognized when an inspected subject with oblique astigmatism sees a perfect circular target.
FIG. 7 is a diagram showing an image that is visually recognized when an inspected person with weak myopia sees a circular target.
FIG. 8 is a diagram showing an image visually recognized when an inspected person with strong myopia sees a perfect circular target.
FIG. 9 is an illustrative view showing a state in which the visual target 24a and the visual target 24b are arranged in the direction in which the visual target is viewed with the longest length.
FIG. 10 is an illustrative view showing a state in which a visual target 24a and a visual target 24b are circumscribed.
FIG. 11 is an illustrative view showing a state in which the visual target 24a and the visual target 24b are arranged orthogonal to the direction in which the visual target is viewed with the longest length.
FIG. 12 is another illustrative view showing a state in which the visual target 24a and the visual target 24b are circumscribed.
FIG. 13 is an illustrative view showing center coordinates of two targets arranged in a direction in which the length of the target is viewed by the examinee as longest as possible.
FIG. 14 is an illustrative view showing an eyeball optical model;
FIG. 15 shows the relationship among the distance L from the screen to the lens front surface of the eyeball optical model, the distance l from the lens front surface of the eyeball optical model to the retina, the distance D between the center points, and the length d on the retina of the eyeball optical model. FIG.
FIG. 16 is a flowchart showing the operation of the optometry system in the present embodiment.
FIG. 17 is a diagram illustrating a state in which target data is displayed when measurement is performed using three targets.
FIG. 18 is a diagram illustrating a state in which target data is displayed when measurement is performed using four targets.
FIG. 19 is a diagram showing a state in which another target data for measuring the astigmatism axis is displayed.
FIG. 20 is a diagram illustrating a case where a linear target is arranged so as to be parallel to a direction in which a perfect circular target is viewed the longest.
FIG. 21 is an illustrative view showing a visual acuity table;
FIG. 22 is an illustrative view showing an astigmatism axis measurement chart;
[Explanation of symbols]
10 Optometry system
12 Optometrist server
14 Central processing unit
16 WWW server
20 storage area
22, 22a Target data
24a, 24b, 24c, 24d
26 Optometry function
28 Eyeball optical parameter determining means
30 Approximate lens power determination means
32 Eyeball optical model determining means
34 Retina upper length calculation means
36 Upper retina length correction means
50 Patient terminal
100 network

Claims (9)

An optometry system for performing eye examination by allowing a subject to visually recognize a target with a single eye at a predetermined distance,
Display means for displaying the target;
Visual target data providing means for providing visual target data for displaying a visual target of a predetermined shape on the display means;
Visual shape acquisition means for acquiring information related to the shape of the inspected person visually recognizing the visual target;
Look including the ocular optical parameter determining means for determining the optical parameters of the eye based on information about the shape of the examinee is viewing the visual target,
The visual shape acquisition means includes
The length of the visual target in which the inspected person is viewing the visual target in the direction in which the inspected person has most visually deformed and viewed the visual target, and the inspected person has viewed the visual target with the most deformation. A visual length measuring means for measuring the length of the visual target in which the examinee in the direction orthogonal to the direction visually recognizes the visual target;
The eye optical parameter determination means includes
The length of the visual target in which the examinee is viewing the visual target in the direction in which the examinee has viewed the visual target most deformed, and the visual inspection of the visual target most deformed by the examinee. An eye optometry system comprising power determining means for determining the spherical power and astigmatism power of the eyeball based on the length of the visual target in which the examinee is viewing the visual target in a direction orthogonal to the determined direction. The target data providing means includes:
Provide optotype data that displays a plurality of optotypes that have the same length from the center to the contour of the optotype and whose display positions can be changed.
The direction measuring means includes
The optometry system according to claim 1 , wherein the direction is obtained by arranging the plurality of optotypes in a direction in which the inspected person deforms and visually recognizes the optotype most. The target data providing means includes:
Provides target data that displays a linear target that can rotate freely with a target whose length from the center of the target to the contour is equal,
The direction measuring means includes
Is arranged parallel to the direction in which the linear optotype was visually the most deformed equal optotypes length from the center to the contour in the examinee to acquire direction, claim 1, wherein Item 3. The optometry system according to Item 2 . The target data providing means includes:
Providing target data for displaying two targets of the same shape movable in the direction of measuring the length of the target on the direction of measuring the length of the target;
The visual length measuring means includes
The length of the target is obtained by obtaining the center coordinates of the target when the subject is moved so that both or one of the targets is moved and placed in a state where the target is visually circumscribed. The optometry system according to claim 1 , wherein the optometry is calculated. The direction in which the inspected person visually deformed and visually modified the target is
Is a direction in which the examinee is the visual length of mark is visible as the longest direction or the examinee is visible that the minimum length of the optotype, according to any one of claims 1 to 4 Optometry system. The optometry system according to claim 1 , further comprising a distance holding unit that maintains a predetermined distance from the display unit to the eye of the subject. The optometry system according to any one of claims 1 to 6 , further comprising light shielding means for preventing light from other than the display means from entering the eye of the subject. The shielding hand stage light from other than said display means to the eye of the examinee to the state in which no incident is
8. The optometry system according to claim 7 , wherein the optometry system is a cylindrical body having an opening that can be in close contact with the screen of the display means and the peripheral portion of the eye of the subject. The visual target displayed on the display means is visually recognized by the subject with one eye ,
Displaying a target having a predetermined shape on the display means;
Obtaining information related to the shape of the inspected person viewing the target;
An optometry program that causes a computer to execute a step of determining optical parameters of an eyeball based on information relating to a shape in which the examinee is viewing the target ,
The step of acquiring information related to the shape of the inspected person visually recognizing the optotype,
Measuring the length of a visual target in which the examinee is viewing the visual target in the direction in which the examinee has deformed and visually recognized the visual target most,
Measuring the length of the target in which the subject in the direction perpendicular to the direction in which the subject has viewed the target most deformed and viewed the target,
Determining optical parameters of the eyeball based on information on the shape that the examinee is viewing the optotype,
The length of the visual target in which the examinee is viewing the visual target in the direction in which the examinee has viewed the visual target most deformed, and the visual inspection of the visual target most deformed by the examinee. An optometry program, comprising: determining a spherical power and an astigmatism power of an eyeball based on a length of a visual target in which a subject in a direction orthogonal to the measured direction is viewing the visual target.

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