Protection factor rating system for protective eyewear

Abstract

A method of rating eyewear includes providing eyewear to be rated, measuring a physical property of the eyewear selected from a group that includes ultraviolet radiation absorption, blue light radiation absorption, infrared radiation absorption, and light blocking capability, transforming the physical property into a rating value, and informing a prospective consumer of the rating value.

Description

FIELD OF THE INVENTION[0001]The present invention relates to the field of eye protection and more particularly to a method of rating sunglasses designed to inform purchasers about the light protective properties of the sunglasses.BACKGROUND OF THE INVENTION[0002]Worldwide there has been an alarming increase in the incidence of skin cancer over the past two decades, particularly in the populated Sunbelt regions. This near epidemic of skin cancer has resulted in many organizations, including the National Skin Cancer Foundation, heightening public awareness of the problem of solar radiation and encouraging preventative measures. One of the most notable preventative changes has been the development of the sun protection factor (SPF) which provides rating for sun protection given to various sunscreen products. The SPF system for sunscreens is based on units of time required for a given skin type to reach erythema condition under selected radiation exposure and ranges from 0 to 50 with in...

AI Technical Summary

Problems solved by technology

It is well-known that sunlight, or solar radiation, at the earth's surface can cause damage to the eye.

Although other parts of our body, including the immune system, may be adversely affected by sunlight, damage to the eye from certain wavelengths of sunlight is well documented.

Since virtually all traditional sunscreens are toxic to the cornea and would interfere with vision, the typical method of sun protection for the eye, beyond normal anatomical and physiological protection, has been the use of sunglasses.

The damaging effect of solar radiation upon the eye is dependent upon the wavelength or energy content of the photons.

Long-wavelength radiation, in the near infrared, is relatively harmless, whereas shorter wavelength radiation, in the near ultraviolet, is very damaging.

Nevertheless, radiation between 380 nm and 1400 nm is damaging to sensitive structures within the eye.

Although visible light is defined by a narrow band of spectral radiation, the eye absorbs radiation beyond that range and can be damaged by such radiation.

However, there is a sudden rise in the amount of damage produced in the retina when the photon energy reaches a wavelength of approximately 510 nm.

Moreover, because this increased toxicity occurs at the border between the perceived colors of green and blue, the phenomenon is referred to as the blue-light hazard.

The UV radiation present in sunlight is not useful for vision.

Clinical experience, evidence from accidental exposures, and other experimental studies show that UV-B is more damaging to the eye, presumably because it has higher energy than UV-A.

However, the retina, if exposed to UV-B radiation, can be damaged.

Cataracts are a major cause of visual impairment and blindness worldwide.

Exposure to UV and intense violet / blue visible radiation is damaging to retinal tissue in laboratory experiments; thus scientists have speculated that chronic UV or intense violet / blue light exposure may contribute to the aging processes in the retina.

It can be removed surgically, but often recurs, and can cause cosmetic concerns and vision loss if untreated.

It can be extremely painful for 1-2 days and can result in temporary loss of vision.

There is some indication that long-term exposure to UV-B can result in corneal degenerative changes.

Solar radiation damage to the eye appears to be cumulative and increases the risk of developing an ocular disorder later in life.

However, consumers typically purchase sunglasses for fashion or comfort reasons rather than protective ones.

And while there is rising public awareness of the benefits of sunscreen and the meaning of sunscreen SPF factors, there is not a similarly standardized and accepted rating system for sunglasses.

However, there are no metric-based requirements for indicating the percentage of radiation the lens absorbs or what wavelengths of radiation are absorbed.

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