GB2292815A - Spectacle frame for auxiliary lenses - Google Patents

Abstract

A spectacle frame is construsted so that it may carry two lenses for each eye. Ears 1 may retain an auxiliary lens, which may be removed for cleaning. <IMAGE>

Description

IMPROVED SPECTACLES SlDny pairs of spectacles otherwise in good condition are discarded because the owners' eyes have changed lnd the lenses no longer suit them.

hitherto it has been that the patient undergoes an eve test with a view to complete replacement of the spectacles or t the very least replacement lenses.

The present invention offers an alternative solution provided no medical reason prevents its use. It is to fit auxiliary strength-adjustment lenses in addition to the prescription lenses already fitted for the l)urpose of compensating for the changes which have taken place in the pntient's eyes.

Analysis of the progressive change which takes place in normal health shows that the mein correction changs is to the " strength " which means that the change applies only to the spherical correction of the total prescription and n simple update of this portion can be made with a low strength mass-produced lens if necessary without the need to remake the spectacles anew. Any other focussing error in the patient's eyes, (stigmatism ), has already been taken care of in the original prescription lenses lnd that correction continues to be effective.

Tn the first application of this invention a spectncles frame is fitted ab initio with means for retaining n second lens for each eye on n permanent basis Figure 1 illustrates how an auxiliary lens may be retained by a modification to the plastic moulding of the frame to include to "earS", ( items 1 ).

behind which the auxiliary lens. is inserted.

The method by which the lens nay be inserted is shown in Figure 2. A twisting action is used. 'tev- easing this action permits the lens to be removed from time to time for cleaning purposes.

In a second application of the invention it has been found feasible to alter the character of the spectacle from "Normal" to "di-focal" b fitting auxiliary bi-focal lenses of dual strength, (standard) or graded

strength, (Variluxp. Having only a low power in terms of dioptres, the required strength is very similar for any patient. expert fitting will be reauired because of the different eye to eye distance of each patient.

In a third aspect of the invention the auxiliary and prescription lenses are interchanged so that the cheaper auxiliary lens goes in the front thereby protecting the prescription lens. This application would be advantageous in some industrial environments, and the function would be similar to approved Industrial Glasses.

In the r'ourth application of this invention a normal spectacle frame is modified to receive means for ret aining an auxiliary lens. The means for doing this ars typically R splayed wire clip forced into small holes drilled in the frame in approximately the same position as the "ears" of Figure 1. A frame so fitted is depicted in Figure 3. Other methods are possible.

Advantageously in all applications of the invention the curvature of adjacent surfaces should be such that the centres do not touch causing scuffing of that part of the lens within the field of view.

Claims (1)

1. (1) A spectacle frame constructed so that it nay carry two lenses for each eye instead of the usual one only, to fulfil the applications (1), (2), and (3) herein before described.

   (2) A spectacle frame modified as described in aspect (4) to enable it to serve the same functions as in Claim (1) (3) Fixtures and fittings as described in aspect (4) to enable a frame to be modified as in aspect (4).