WO2001081987A1 - Optical equipment forming an additional surface in high position for spectacles - Google Patents

Abstract

The invention concerns an equipment consisting of a support (7-10) capable of being temporarily secured to a frame of spectacles (1) provided with full field lenses (5a, 5b) and additional positive power lenses (11a, 11b), adapted to be urged to be superimposed on said full field lenses, in the zone through which the wearer looks when he observes an object placed horizontally or above eye level. The additional lenses are multifocal. The equipment enables to modify temporarily the correction provided by said eyeglass lenses.

Description

Optical equipment forming additional face in high position for glasses.

The present invention relates to optical equipment essentially intended for presbyopes. Presbyopia, which results from the progressive inability of the lens to change its shape enough to allow satisfactory near vision (i.e. clear vision of objects located less than 40 cm), is most corrected often: - either by wearing full field near vision glasses which can only be worn to carry out near vision tasks (reading, DIY, etc.) and which therefore need to be removed - and often replaced by another pair of glasses - to allow far vision;

- either by wearing glasses called "half-moon" when the subject does not need far vision correction or is corrected, in far vision, by wearing contact lenses; - either by wearing glasses or multifocal contact lenses, progressive or not, which correct both near and far vision, with most often a correction for intermediate vision (distance of outstretched arm). Except in the first case, the clear vision in far vision is obtained only when the subject looks through the upper part of his glasses or, in the case of half-moons, over the glasses, hence the difficulties that '' experience some people, for example, going down stairs while wearing multifocal lenses, the steps being at a distance of vision from afar when they are seen through the lower part of the glasses.

Conversely, and always with the same exception, clear vision in near or intermediate vision is only obtained when the subject looks through the lower part of his glasses. However, he may have to observe a object located near it but in a horizontal direction or in height.

The subject may, moreover, have to constantly pass from the observation of an object visible through the lower part of his glasses (such as a computer keyboard) to that of an object visible through the middle or top part of his or her lenses (such as a computer screen), objects that are both near vision distance, or one of which is near vision distance and the other within intermediate viewing distance.

This problem has been known for a long time and, in an attempt to remedy it, the subjects adopt abnormal and tiring heads, but which allow them, as far as possible, to observe close objects located horizontally or in height across the bottom of their glasses. A technical solution to this problem has been the manufacture of very special visible multifocal glasses which have a near and / or intermediate vision zone, not only in the lower part of the glasses, but also in their upper part. Such glasses which have existed for many years have only received confidential distribution, their specificity making them expensive and unusable outside the context for which they were manufactured. In addition, they permanently reduce the far field of vision, which can have drawbacks in the area of vigilance and safety (for example, in the case of airplane pilots who have to observe control dials placed at a short distance, at a height - and for which these special lenses were essentially designed - but which may also have to visually grasp, acutely and without delay, an event occurring outside the device) .

Another solution has been proposed by US-A-5 118 178 which provides optical equipment consisting of: a support adapted to be temporarily secured to the assembly formed by a spectacle frame and the full field glasses which equip it, called "base glasses", and additional glasses adapted to be superimposed on said base glasses, said additional glasses being corrective glasses of positive power extending over a height such that, when they are in place on a spectacle frame carried by a subject, they are positioned in the zone through which this subject looks when he observes an object placed horizontally or in height.

In other words, their upper edge and their lower edge are located, respectively, substantially at the level of the upper edge and substantially at mid-height of said base glasses, it being understood that, when reference is made to the height of glasses basic, we refer to full field glasses of a conventional average height, that is to say of the order of 40 to 55 mm.

In known equipment, the additional lenses are monofocal and they have a power of between + 0.5 and + 1.25 diopters. More specifically, US-A-5 118 178 proposes an automatic selection of the power within this range, by jump of + 0.25 diopters, according to the age of the carrier:

It is therefore a correction mode which only takes age into account as a parameter. Yet another parameter should not be ignored, namely the desired net viewing distance depending on the direction of gaze.

The present invention proposes to remedy this drawback and, to this end, it provides equipment for the aforementioned type, but in which the additional lenses are multifocal.

Depending on the desired result (short distance clear vision of an object observed through the lower part of the additional lenses or short distance clear vision of an object placed in height observed through the upper part of the additional lenses), the power of said additional glasses will be greater at their lower edge than at their upper edge, or vice versa.

In a preferred embodiment, the additional glasses will have a power of the order of + 1 diopter at their lower edge and a power of the order of + 0.25 diopter at their upper edge, or vice versa .

In a first variant of the invention, the additional lenses are bifocal.

In a second, preferred variant, the additional glasses are progressive, it being understood that this term must be taken in the sense of glasses of progressively variable power, and not necessarily in the sense of glasses of progressively increasing power towards the lower edge of the glass. The additional glasses can therefore be "progressive" according to this restrictive meaning, or on the contrary "degressive".

Advantageously, the additional glasses can be colored, for example to avoid visual fatigue when working on a screen, and / or be treated with anti-reflection.

The equipment according to the invention must remain economical and, to do this, it will generally be manufactured as a standard article. However, the average pupillary distance of the population for which it is intended must be taken into account. For this purpose, for the European population, we can use a standard pupillary distance in intermediate vision of 62 mm for women and 64 mm for men. Of course, we can also manufacture 1 equipment on demand and take into account the real pupillary distance of the wearer.

The support for the additional lenses adapted to be temporarily secured to the assembly formed by the spectacle frame and the base lenses can be of any type, in particular one of the types used to temporarily mount a solar face on a frame. glasses. The support for the additional lenses may take the form, for example, of a clamping device comprising spring jaws adapted to overlap, and to clamp between them, the face of the spectacle frame and part of the base lenses, on either side of the mount bridge.

As a variant, provided that the material of the frame is magnetizable, the meeting between the frame and the support for the additional lenses may be obtained by incorporating magnets in said support.

Preferably, the additional glasses will be pivotally mounted on their support between a service position in which they partially cover the basic glasses and a retracted position in which they project away from said basic glasses, making with them an angle of at least about 90 °, which clears the visual field. Thus, if the wearer must momentarily observe a point located at a far vision distance, for example an interlocutor, he can simply rotate the additional lenses to remove the effect.

In addition, the fact that the equipment is instantly retractable is an important factor in terms of safety (see the case of aircraft pilots mentioned above, that of machine operators, etc.) and practical life.

An embodiment of the invention is described in detail below with reference to the single figure of the accompanying drawing which is a front elevational view of the equipment according to the invention in place on a spectacle frame and in position on duty. There is shown, in dotted lines, in the drawing the elements of a frame 1 of glasses necessary and sufficient to understand the invention, namely the face 2, the bridge 3 and the hinges 4 of branches. The plates and branches have been omitted so as not to overload the design. The frame 1 is equipped with full field lenses 5a, 5b called basic lenses in the present description and in the claims, offering correction in near vision only in their lower part. It can be both double or triple focus glasses as well as progressive glasses. The upper part of the lenses can be flat or offer a correction in far vision.

The equipment according to the invention is, for its part, shown in solid lines, except as regards its parts which are located in the background, behind the basic lenses.

This equipment consists of a support comprising a pair of suitable pliers, each to overlap and pinch the assembly formed by the face 1 and a base glass 5a or 5b between its jaws, one of which 6a, 6b is fixed and the other, mobile. Only one, 6a or 6b, of the jaws of each clamp is visible in the drawing, the other jaw being hidden by the one which is represented. The clamps are held in the closed position by a spring whose force can be overcome by squeezing, between the thumb and forefinger, a lever 7 towards a projection 8, the lever 7 being integral with the movable jaws of each clamp and the projection 8 being the fixed jaws of each clamp.

Between the lever 7 and the projection 8 is inserted a U-shaped part whose core 8 forms an axis of rotation and whose wings 10 are adapted to serve as a support for mounting a pair of glasses 11a, 11b, by drilling said glasses and placement of screws 12. As can be clearly seen in the drawing, the glasses 11a, 11b, called additional glasses in the present description and in the claims, have a height h approximately equal to half the height of the basic glasses 5a, 5b. In other words, their upper edge 12 is substantially at the upper edge 13 of the base lenses and their lower edge 14 is substantially halfway up the base lenses. By "appreciably", it is meant that the correspondence is approximate taking into account the general shape of the frame, therefore of the base lens, of which (1) the upper edge may as well be almost straight as very curved, the drawing showing a situation intermediate, and (2) the height is also variable, especially with fashion. The additional lenses 11a, 11b have a positive power and are multifocal (such as bifocal or progressive in the broad sense).

In one of the applications of the invention, the power of the additional lenses, at their upper edge 12, is less than their power at their lower edge 14. In this way, the clear vision distance allowed by l The equipment is longer when the wearer looks through the upper part of the additional lenses than through their lower part. More specifically, the additional glasses can have a power of 1 order:

+ 1 diopter at the level of their lower edge which allows a remotum of approximately 1 meter, that is to say a clear vision at "arm distance", when the wearer looks horizontally, through the lower part additional lenses, and + 0.25 diopters at their upper edge, which allows a remotum of about 4 meters, when the wearer looks up, through the upper part of the additional lenses.

The installation of the equipment according to the invention will therefore temporarily transform the basic equipment into so-called "proximity" glasses.

The equipment according to the invention thus constitutes a simple and economical means allowing any wearer of a correction of near vision in the lower part of his basic lenses to benefit from an intermediate vision clear, with a large field of vision in the horizontal plane, when he looks through the upper part of his glasses, thus avoiding him the adoption of artificial postures and the stresses on the cervical vertebrae which result.

To temporarily retract the additional glasses, it suffices to rotate the U-shaped support around its core 9 until the moment when the additional glasses 11a, 11b occupy a position substantially perpendicular to the base glasses 5a, 5b.

As indicated above, the power of the additional lenses, at their upper edge 12, could be greater than their power at their lower edge 14. In this way, the clear vision distance allowed by the equipment would be shorter when the wearer looks through the upper part of the additional lenses than through their lower part.

The present invention is capable of providing visual comfort to many wearers. It was mentioned above the case of people working on computer and who are faced with the problem of incessant change of "viewing distance" / "gaze direction" between the keyboard and the screen. The same applies for example to musicians (instrument, score). It is also useful in all circumstances involving observation at medium distance made horizontally or above the horizontal (aircraft pilots, electricians, handymen, dentists, radiologists, etc.).

In addition, although the equipment according to the invention is essentially intended for presbyopics, it can be usefully prescribed, for specific medical reasons, to young or adult subjects who are not presbyopic.

It is understood that the invention is not limited to the embodiment described and shown. In particular, the structure of the support for the additional glasses can be arbitrary provided that it allows an easy, fast and stable installation on the glasses frame, and an equally easy and quick removal. However, it is preferable for the support to be pivotable so that the additional lenses of the frame can be retracted instantly without separating the equipment from the frame.

Claims

1 - Optical equipment consisting of: a support (7-10) adapted to be temporarily secured to the assembly formed by a spectacle frame (1) and the full-field lenses (5a, 5b) which equip it, called " base lenses ", and additional lenses (11a, 11b) adapted to be superimposed on said base lenses (5a, 5b), said additional lenses (5a, 5b) being corrective lenses of positive power extending over a height (h) such that, when they are in place on a spectacle frame carried by a subject, they are positioned in the zone through which this subject looks when he observes an object placed horizontally or in height, characterized in that said additional lenses (11a, 11b) are multifocal. 2 - Equipment according to claim 1, characterized in that the power of said additional glasses (11a, 11b) is greater at their lower edge (14) than at their upper edge (12). 3 - Equipment according to claim 2, characterized in that said additional glasses (11a, 11b) have a power of the order of + 1 diopter at their lower edge (14) and a power of the order of + 0 , 25 diopters at their upper edge (12). 4 - Equipment according to claim 1, characterized in that the power of said additional glasses (11a, 11b) is weaker at their lower edge (14) than at their upper edge (12). 5 - Equipment according to claim 4, characterized in that said additional glasses (11a, 11b) have a power of the order of + 0.25 diopters at their lower edge (14) and a power of the order of + 1 diopter at their upper edge (12). 6 - Equipment according to any one of claims 1 to 5, characterized in that the additional glasses (11a, 11b) are bifocal. 7 - Equipment according to any one of claims 1 to 5, characterized in that the additional glasses (11a, 11b) are progressive. 8 - Equipment according to any one of claims 1 to 7, characterized in that said additional glasses (11a, 11b) are pivotally mounted on their support (7-10) between a service position in which they partially cover the glasses of base (5a, 5b) and a retracted position in which they project away from said base glasses, at an angle with them of at least about 90 °.