US 7,604,350 B2Granted

Method for calculating an ophthalmic lens and corresponding lens

AssigneeIndo Internacional, S.A.

InventorsJuan Carlos Dursteler Lopez, Javier Vegas Caballero, Roberto Villuela Arroyo, Enric Fontdecaba Baig, Juan Esteban Palomar Burdeus

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Abstract

Method for calculating an ophthalmic lens comprising [a] calculating and constructing a computational model of an initial lens with a given prescription, [b] calculating the three sections of the optical path traveled by rays using the computational model, [c] determining the first surface of a lens equivalent to the initial lens, and [d] calculating the second surface of the equivalent lens by plotting the rays through the equivalent lens and determining their point of intersection with the second equivalent surface. Each ray has an equivalent optical path equal to the initial optical path, or has at least one of the sections of the equivalent optical path equal to the corresponding section of the initial optical path. The equivalent lens thus calculated is the ophthalmic lens that is the object of the invention.

Claims68

Dependent claims

A method for calculating an ophthalmic lens, said ophthalmic lens comprising a first surface opposite the eye of a user, and a second surface orientated towards the user's eye, wherein said ophthalmic lens has a first power in its far vision area and a second power in its near vision area and characterized in that it comprises the following steps:

a. calculating an initial lens from a given prescription, where said initial lens defines a first initial surface and a second initial surface;
b. constructing a computational model of said initial lens;
c. first plotting of a set of rays using said computational model;
d. calculating an initial optical path traveled by each ray using said computational model, wherein said initial optical path is the sum of three sections, a first section before said first initial surface, a second section between said first initial surface and said second initial surface and a third section after said second initial surface;
e. pre-selecting a first equivalent surface of an equivalent lens to said initial lens, wherein said first equivalent surface is selected from the group consisting of:
a spherical surface and an aspherical surface, and has a power equal to the mean value between said first power and said second power;
and
f. calculating a second equivalent surface of said equivalent lens by means of the plotting of each ray through said equivalent lens and determining the point of intersection of each of said rays with said second equivalent surface, where, in order to determine the point of intersection with said second equivalent surface it is necessary that:
each ray has an equivalent optical path equal to said initial optical path, or each of said rays has at least one of the sections of said equivalent optical path equal to the corresponding section of said initial optical path, so that said equivalent lens thus calculated is said ophthalmic lens.

6 more elements

a. calculating an initial lens from a given prescription, where said initial lens has a first initial surface and a second initial surface;
b. constructing a computational model of said initial lens;
c. first plotting of a set of rays using said computational model;
d. calculating an initial optical path traveled by each ray using said computational model, wherein said initial optical path is the sum of three sections, a first section before said first initial surface, a second section between said first initial surface and said second initial surface and a third section after said second initial surface;
e. pre-selecting a first equivalent surface of an equivalent lens to said ophthalmic lens, wherein said first equivalent surface is a progressive surface different from said first initial surface;
and
f. calculating a second equivalent surface of said equivalent lens by means of the plotting of each ray through said equivalent lens and determining the point of intersection of each of said rays with said second equivalent surface, where, in order to determine the point of intersection with said second equivalent surface it is necessary that:
each ray has an equivalent optical path equal to said initial optical path, or each of said rays has at least one of the sections of said equivalent optical path equal to the corresponding section of said initial optical path, so that said equivalent lens thus calculated is said ophthalmic lens.

5 more elements

The method for calculating an ophthalmic lens, said ophthalmic lens comprising a first surface opposite the eye of a user, and a second surface orientated towards the user's eye, wherein said ophthalmic lens having a first power in its far vision area and a second power in its near vision area and comprising the following steps:

a. calculating an initial lens from a given prescription, where said initial lens defines a first initial surface and a second initial surface;
b. constructing a computational model of said initial lens;
c. first plotting of a set of rays using said computational model;
d. calculating an initial optical path traveled by each ray using said computational model, wherein said initial optical path is the sum of three sections, a first section before said first initial surface, a second section between said first initial surface and said second initial surface and a third section after said second initial surface;
e. pre-selecting a first equivalent surface of an equivalent lens to said ophthalmic lens, wherein said first equivalent surface is selected from the group consisting of:
a spherical surface and an aspherical surface and has a power between said first power and said second power;
and
f. calculating a second equivalent surface of said equivalent lens by means of the plotting of each ray through said equivalent lens and determining the point of intersection of each of said rays with said second equivalent surface, where, in order to determine the point of intersection with said second equivalent surface it is necessary that:
each ray has an equivalent optical path equal to said initial optical path, or each of said rays has at least one of the sections of said equivalent optical path equal to the corresponding section of said initial optical path, so that said equivalent lens thus calculated is said ophthalmic lens.

6 more elements

Dependencies are inferred from the claim text.