Filter for eye cone cells protection

Patent metadata

Field	Value
Publication number	US-12248202-B2
Application number	US-202017440101-A
Country	US
Kind code	B2
Filing date	Mar 13, 2020
Priority date	Mar 18, 2019
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

The invention relates to filter dedicated to protect eye cone cells and method associated. The eye cone cells protecting filter is intended to be applied to a transparent surface and to filter incident light for preventing eye cone cells of a user, from damages due to illumination at physiological light levels on the eye of said user, and having spectral characteristics to i) filter light wavelengths between 405 and 465 nanometers, and ii) transmit a filtered light reaching the eye cone cells and having a harmfulness on said eye cone cells under a predefined maximum threshold.

First claim

The invention claimed is:

1. An eye cone cells protecting filter, intended to be applied to at least one transparent surface, to filter incident light on said transparent surface, for preventing eye cone cells of a user, from damages due to illumination at physiological light levels on the eye of said user, and having spectral characteristics to:
filter light wavelengths between 405 and 465 nanometers; and
transmit a filtered light reaching the eye cone cells and having a harmfulness on said eye cone cells under a predefined maximum threshold, said predefined maximum threshold being determined based on a tolerated level of light hazard on cone cell (LHC) parameter;

wherein the eye cone cells protecting filter further comprises:
an active matrix for filtering incident light on said transparent surface;
an input for receiving measurements of transmitted light between the transparent surface and the eye
a processor for computing the spectral characteristics of the eye cone cells protecting filter on the basis of at least:
said transmitted light measurements; and
said predefined maximum threshold, and for controlling the active matrix to filter incident light on the basis of said computed spectral characteristics.

2. The eye cone cells protecting filter according to claim 1 , wherein said spectral characteristics comprise a filtering peak between 425 and 445 nanometers.

3. The eye cone cells protecting filter according to claim 1 , wherein said spectral characteristics comprise a filtering peak between 425 and 445 nanometers, and the active matrix comprises an electrochromic material.

4. The eye cone cells protecting filter according to claim 1 , wherein the filter is applied as a darkening tint to said transparent surface and is configured to absorb a fixed proportion of incident light.

5. A method for computing spectral characteristics of an eye cone cells protecting filter according to claim 4 , comprising:
a′) obtaining, for a solar incident light and within at least one predetermined wavelengths range, a light hazard on cone cells (LHC) defined by a percentage of eye cone cells death relatively to a solar incident light dose;
b′) estimating a light dose on the eye, due user's data, within said predetermined wavelengths range and during a predefined time;
c′) estimating, on the basis of said estimated light dose, a current cell death hazard percentage within said given time range; and
d′) if said current cell death hazard percentage is above said predefined maximum threshold, computing said spectral characteristics to lower said current transmitted light until the current cell death hazard percentage is below said predefined maximum threshold.

6. A computer program for computing spectral characteristics of an eye cone cells protecting filter according to claim 4 , the computer program comprising instructions codes for performing a method for computing spectral characteristics of an eye cone cells protecting filter, comprising:
a′) obtaining, for a solar incident light and within at least one predetermined wavelengths range, a light hazard on cone cells (LHC) defined by a percentage of eye cone cells death relatively to a solar incident light dose;
b′) estimating a light dose on the eye, due user's data, within said predetermined wavelengths range and during a predefined time;
c′) estimating, on the basis of said estimated light dose, a current cell death hazard percentage within said given time range; and
d′) if said current cell death hazard percentage is above said predefined maximum threshold, computing said spectral characteristics to lower said current transmitted light until the current cell death hazard percentage is below said predefined maximum threshold;

when the instructions are run by a processor.

7. The eye cone cells protecting filter according to claim 1 , wherein said predefined maximum threshold is determined on the basis of at least one element among:
a type of activity of the user;
physiological parameters of the user;
an age of the user; and
an average dose of light to which said user is exposed.

8. The eye cone cells protecting filter according to claim 1 , configured to absorb a proportion of incident light higher than 99% at wavelengths below a critical wavelength.

9. The eye cone cells protecting filter according to claim 8 , wherein the critical wavelength is between 425 nanometres and 445 nanometres.

10. The eye cone cells protecting filter according to claim 1 , wherein said predefined maximum threshold is determined further to limit a power density to 0,2 mW/cm 2 of light reaching the eye cone cells.

11. A method for computing spectral characteristics of an eye cone cells protecting filter according to claim 1 , comprising:
a) obtaining, for a solar incident light and within at least one predetermined wavelengths range, a light hazard on cone cells (LHC) defined by a percentage of eye cone cells death relatively to a solar incident light dose;
b) measuring an irradiance of a current transmitted light between the transparent surface and the eye, within said predetermined wavelengths range, and estimating, on the basis of said transmitted light measurements, a current cell death hazard percentage;
c) if said current cell death hazard percentage is above said predefined maximum threshold, computing said spectral characteristics to lower said measured transmitted light; and
repeating b) and c) until the current cell death hazard percentage is below said predefined maximum threshold.

12. The method according to claim 11 , wherein said current transmitted light is determined within a plurality of successive wavelengths ranges, and said current cell death hazard percentage is given by a sum of current transmitted light intensities in each of said wavelengths ranges multiplied by said light hazard on cone cells (LHC).

13. The method according to claim 11 , wherein said current transmitted light is determined within a plurality of successive wavelengths ranges, and said current cell death hazard percentage is given by a sum of current transmitted light intensities in each of said wavelengths ranges multiplied by said light hazard on cone cells (LHC), and wherein said spectral characteristics are given by a light transmission rate Tlens(λ) defined, for each of said successive wavelengths ranges (λ), by:
Tlens=TH/CD, where:
TH is the predefined maximum threshold; and
CD is the current cell death hazard percentage.

14. A computer program for computing spectral characteristics of an eye cone cells protecting filter according to claim 1 , the computer program comprising instructions codes for performing a method for computing spectral characteristics of an eye cone cells protecting filter, comprising:
a) obtaining, for a solar incident light and within at least one predetermined wavelengths range, a light hazard on cone cells (LHC) defined by a percentage of eye cone cells death relatively to a solar incident light dose;
b) measuring an irradiance of a current transmitted light between the transparent surface and the eye, within said predetermined wavelengths range, and estimating, on the basis of said transmitted light measurements, a current cell death hazard percentage;
c) if said current cell death hazard percentage is above said predefined maximum threshold, computing said spectral characteristics to lower said measured transmitted light; and
repeating b) and c) until the current cell death hazard percentage is below said predefined maximum threshold;

when the instructions are run by said processor.

Assignees

• Essilor Int
• Univ Sorbonne

Inventors

• Marie Mélanie
• Picaud Serge
• Fradot Valérie
• SAHEL José
• Villette Thierry
• Barrau Coralie
• Ehrismann Camille

Classifications

• G02C7/101

  having an electro-optical light valve (electro-optical elements per se G02F) · CPC title

• G02C7/102 Primary

  Photochromic filters · CPC title

• G02C7/10 Primary

  Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses · CPC title