VISUAL AID ESPECIALLY FOR WEAK-SIGHTED PERSONS

Abstract: Visual aid especially for weak-sighted persons and compris­ ing a sleeve (1) into which at least one lens (2) is fittable having the desired optical properties. The sleeve (1) is intended to be fitted into an opening (3) in a spectacle glass (4) and be fixed in an optional position for individual adjustment of the distance bet­ ween the person's cornea and the lens surface.

Description: The present invention relates to optical devices suitable for use by persons suffering from reduced vision. More particularly, the present invention is related to a visual aid of simple construction and which is easily adaptable to the ophtalmic needs of the visually-handicapped. Persons having a strongly reduced ability to see need powerful binocular magnifying glasses for close seeing, e.g. reading. Besides a number of other corrections can be necessary, e.g. cylindric correction, prismatic effect, etc. The visual aids which up to now have been available for this category of patients are relatively costly, as they have to be specially made after the individual requirements of the optical characteristics of the lens as well as of the distance between the cornea and the lens surface. Prior art vision aids such as those, for instance, known from US-A-3592525 and US-A-2025593 basically are lenticular magnifying pieces consisting of small lenses of special design, e.g. unitary of bifocal lenses which are fixedly cemented in an appropriate bore in a pair of carrying spectacle glasses. A quite different vision aid is disclosed in US-A-4429959 where it is proposed to solve certain problems of conventional systems comprised of common binoculars attached to a pair of spectacles. Accordingly, a separate binocular carrying support is provided in the form of hingedly connected clear plastic plates which are movably mounted onto a spectacle frame in front of the spectacle glasses thereof. Common monocular or binocular lenses are fixedly mounted by screw connection in an aperture of the glass plates. The latter device, however, is still bulky and unaesthetic. US-A-4195918 discloses a visual aid according to the preamble of claim 1. The object of the present invention is to provide a flexible and less costly visual aid, which meets high requirements for individual adjustment as well as ease with which it can be handled. The invention, in its broadest scope, contains the features as defined in claim 1. Further and preferred embodiments of this invention are defined in the appending subclaims. The invention will now be closer described with reference to an embodiment shown in the accompanying drawing. Figure 1 shows a pair of spectacles provided with the visual aid according to the invention. Figure 2 shows the sleeve and a pair of lenses intended to be fixed in the sleeve. Figure 3 shows a pair of spectacles which, additionally to the aid according to the present invention is also provided with a distance alt. reading segment. The visual aid comprises a substantially cylindric sleeve 1 in which one or possibly two lenses 2 can be fitted, one at each and of the sleeve. The device can be compared with a magnifying glass, which held close to the eye gives a magnified image of an object which is held just in front of the lens. The sleeve 1 is intended to be fitted into a cut opening 3 in a spectacle glass 4, at which its position can be adjusted for individual adaptation of the distance between the patient's cornea and the lens surface. After this adjustment the sleeve is preferably fixed to the spectacle glass 4, e.g. by gluing. The sleeve 1 is preferably on its inside at both ends provided with a groove 5, in which the lens 2 can be snap-locked. Thus the lens 2 needs not be secured by screws. The lens can easily be removed from the sleeve 1 by means of a suction cup. The opening 3 in the spectacle glass 4 can either be arranged centrally therein, as is shown in figure 1 , which is preferred if the spectacles are intended to be used only for close seeing, e.g. reading. If the spectacles are to be used both for distance and close seeing the opening 3 and the sleeve 1 respectively are made smaller and are preferably placed in the upper part of the spectacles, as the patient at reading must hold the text in front of him very close to the eyes. The spectacle glass 4 is at its lower part provided with a distance segment 6. It is of course also possible to place the distance segment on the upper part and the lens performing the function of a reading portion at the lower part of the spectacle glass. It is obvious that this system offers a great flexibility and good possibilities to combinations. One lens can e.g. provide a spherical correction while the other lens provides the desired cylindrical correction. The lenses may also be given a prismatic effect, which influences the optical centre at close seeing and which is required for correction of certain visual defects. The system may also be used at the performance of precision works, e.g. goldsmith's work, in order to provide a binocular vision with magnification. The invention is of course not limited to the embodiments shown but a plurality of modifications are possible within the scope of the claims. It is e.g. obvious that the sleeve can have other geometric shapes than cylindric.

Claims: A visual aid for improving vision, in particular of a weak-sighted person, comprising a pair of spectacles having a pair of glasses, each of which is provided with magnifying and/or correcting optical means positioned in use in front of one eye of the wearer, wherein said means is in the form of a tubular sleeve (1) containing at least one lens (2) which has desired optical properties for the particular eye, the sleeve (2) being received within an opening (3) provided in the corresponding spectacle glass (4) with the exterior shape of the sleeve (1) matching the shape of its corresponding opening (3), characterized in that the position of each sleeve (2) in each spectacle glass (4) is adjustable by sliding of the sleeve (1) within its corresponding opening (3) in the spectacle glass for individual adjustment of the distance between the cornea of the particular eye and the lens, and in that each lens is interchangeably fitted in its sleeve. A visual aid according to claim 1, characterized in that each sleeve (1) is provided with means (5) for snap-locking the lens (2) to the sleeve. A visual aid according to claim 1 and 2, characterized in that each sleeve (1) is provided on its inside at both ends with a groove (5) in which the lens or lenses (2) can be interchangeably fitted. A visual aid according to any of claims 1 to 3, wherein each sleeve (1) has a regular cylindrical housing and each spectacle glass (4) has a corresponding circular opening (3) matching the size of said cylindrical housing. A visual aid according to claim 4, wherein each sleeve contains two lenses which are snap-locked in their respective groove (5) provided on the inside at both ends of the sleeve (1). A visual aid according to any one of claims 1 to 5, wherein each sleeve (1) is positioned centrally in the corresponding spectacle-glass (4) for close seeing. A visual aid according to any one of claims 1 to 5, wherein the sleeve is of small diameter and is positioned either in the upper or in the lower part of the corresponding spectacle glass and wherein the other part, e.g. the lower part, may be provided with a distance segment (6), thereby allowing both distance and close seeing.

Inventors: HELLSTROEM, LARS, Hellström, Lars
Applicants: N.V. OPTIMED
Application year: 1985
Main classification: G02C7
IPC codes: G02C7