GB1302879A - - Google Patents

Abstract

1302879 Eye-examining apparatus A G ORSZAG 16 Dec 1969 [19 Dec 1968] 61330/69 Heading G2J To determine the optical axis of the eye, light from a source is reflected from a surface attached to the front-face of the eye, or from the front-face itself (the cornea) or from the retina. The axis is determined by observing the position of the reflected image, for example by a television camera. The surface attacked to the eye may be a contact lens having a plane reflection facet. To relate the position of the optical axis to the head of the observer, the optical system is attached to a helmet worn by the observer, the position of which may be determined optically or by mechanical pick-ups. In the case where the incident light is reflected from the retina, the eye lens forms an image at the infinity of the source radiation which is re-imaged at the detector. Non- visible radiation is employed to prevent dazzling the observer. The image is formed of blood vessel groups at the retina and the image position is determined by correlation with a photograph. Additionally, the excitation of the fluorescent areas of the retina may be used to form an external image.