FR2814819A1

FR2814819A1 - Progressive lens for correcting presbyopia has distant vision centre corresponding to pupillary divergence for distant vision

Info

Publication number: FR2814819A1
Application number: FR0012630A
Authority: FR
Inventors: Xavier Carriou
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-29
Filing date: 2000-09-29
Publication date: 2002-04-05
Anticipated expiration: 2020-09-29
Also published as: FR2814819B1

Abstract

The progressive lens has its distant vision centre corresponding to the pupillary divergence for distant vision. Its near vision centre corresponds to the pupillary divergence for vision at a distance equivalent to the inverse of the accommodation remainder calculated in diopters. The lens is also equipped with a prism on the level of the near vision centre equivalent to the power of the addition at a metric angle, and having its base towards the wearer's nose.

Description

La présente invention concerne un verre progressif préservant la relation ac- commodation convergence. Les verres progressifs actuels ont un centre de vision de loin correspondant à l'écart pupillaire de vision de loin et un centre de vision de près correspondant à l'écart pupillaire de près soit un décalage de 2 à 3 mm suivant les modèles. The present invention relates to a progressive lens preserving the convenience-convergence relationship. Current progressive lenses have a far vision center corresponding to the pupillary distance vision distance and a near vision center corresponding to the pupil distance distance, i.e. an offset of 2 to 3 mm depending on the model.

Ces verres progressifs nécessitent de faire un effort de convergence pour voir de près. Le moindre petit défaut de convergence empêche le porteur de regarder dans le canal de vision et de voir nettement. Pour les progressifs actuels, plus le verre à une addition importante plus le canal est étroit et moins il y a de rapport entre l'accommodation et la convergence. Cette gymnastique obligatoire est très contraignante et amène parfois les yeux à se relâcher et ainsi à avoir une vision double et floue. l'invention permet de remédier à ces inconvénients. En effet selon une forme préférentielle le centre de vision de près correspond à l'écart de vision pour une distance égale à l'inverse du reste accommodatif, soit environ 2 mm pour une addition de 1 dioptrie, 1 mm pour une addition de 2 dioptries et 0 mm pour une addition de 3 dioptries. Comme le centre n'est pas dans l'alignement de l'objet il est nécessaire de compenser ce décalage par un prisme égal approximativement à la puissance de l'addition en angle métrique soit environ 1 angle métrique pour une addition de 1 dioptrie, 2 angles métriques pour une addition de 2 dioptries et 3 angles métriques pour une addition de 3 dioptries. These progressive lenses require a convergence effort to see close up. The slightest defect in convergence prevents the wearer from looking into the vision channel and seeing clearly. For current progressive, the more the glass has a large addition the narrower the channel and the less there is a relationship between accommodation and convergence. This compulsory gymnastics is very restrictive and sometimes causes the eyes to relax and thus have a double and blurred vision. the invention overcomes these drawbacks. In fact, according to a preferred form, the near vision center corresponds to the vision difference for a distance equal to the inverse of the accommodative remainder, that is to say about 2 mm for an addition of 1 diopter, 1 mm for an addition of 2 diopters and 0 mm for an addition of 3 diopters. As the center is not in alignment with the object, it is necessary to compensate for this offset with a prism approximately equal to the power of the addition in metric angle, i.e. approximately 1 metric angle for an addition of 1 diopter, 2 metric angles for an addition of 2 diopters and 3 metric angles for an addition of 3 diopters.

Selon une forme préférentielle, la méridienne qui va du centre de vision de loin au centre de vision de près est compensée par un prisme égal à la valeur de l'addition pour chaque point de la méridienne, soit pour une addition total de 2 dioptries l'addition au centre de vision intermédiaire pourrait être de 1 dioptrie et donc la valeur prismatique en ce point serait d'environ 1 angle métrique. Pour la vision de loin l'addition en ce point est nulle, il n'y a pas de prisme Selon une variante, quelque soit l'addition le centre de vision de près correspond à l'écart pupillaire de vision de loin et un prisme de 3 angles métriques compense l'absence de convergence en vision de près. cette variante concerne des cas de phories, de strabismes, d'amblyopie monoculaire ou d'absence de convergence. Il est accompagné parfois d'un prisme constant sur toute la surface du verre.According to a preferred form, the meridian which goes from the far vision center to the near vision center is compensated by a prism equal to the value of the addition for each point of the meridian, ie for a total addition of 2 diopters l Addition to the intermediate vision center could be 1 diopter and therefore the prismatic value at this point would be around 1 metric angle. For far vision the addition at this point is zero, there is no prism According to a variant, whatever the addition the near vision center corresponds to the pupillary distance vision and a prism of 3 metric angles compensates for the lack of convergence in near vision. this variant concerns cases of phoria, strabismus, monocular amblyopia or lack of convergence. It is sometimes accompanied by a constant prism over the entire surface of the glass.

Claims

1) Progressive lens characterized in that the far vision center corresponds to the pupillary distance from far away and that the near vision center of the lens corresponds to the pupillary distance for vision at a distance equal to the inverse of the remains accommodative calculated in diopters. This lens is fitted with a prism at the near vision center equal to the power of the metric angle addition. This prism has its base oriented on the nasal side.

2) Progressive lens characterized in that the near vision center of the lens has the same distance as that from a distance This lens is fitted with a prism at the near vision center of around 3 metric angles, nasal base.

3) progressive lens characterized according to claim 1,2, the meridian of which is compensated by a prism equal to the power of the metric angle addition of the nasal base for each of the points making up this line which goes from the center of far vision to in the near vision center.

4) Progressive lens characterized in that the far vision center corresponds to the pupillary distance from a distance and that the near vision center of the lens has a gap between that of far vision and that of near vision This lens is equipped with a prism at the near vision center equal to the value in metric angle to compensate for the offset with respect to a pupil distance of near vision.

5) progressive lens characterized according to claim 4, the meridian of which is itself compensated by a progressive nasal base prism ranging from zero metric angle in far vision to the value of the prism in metric angle for near vision.