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What is
UV light
► Ultra
violet translates to beyond violet in Latin. This
reference is to its comparison of wavelength to the visible light
spectrum, violet being the shortest wavelength of the visible light
spectrum. Ultra Violet rays are shorter than violet rays, but longer
than X-rays which have
electromagnetic radiation characteristics that
may be extremely dangerous.
► Ultra Violet
rays are also known as
deoxidizing rays and chemical rays for its electro magnetic
radiation properties.
►
There
are many form of UV light, UVA and UVB are both common in ouratmosphere.
UV’s
Damaging effects to the eye
► Excessive
ultra violet light exposure to the eyes’
intraocular lens, which protects the
retina, can cause severe damage to the eye.
► UVB light is
the more harmful light to the eye. Excessive UVB light can cause
photokeratitis
(also
known as Welder's flash, Arc eye, Arc flash, Flash Burns, and/or
Corneal Flash Burns) and may also induce
cataracts,
pterygium, and
pinguecula.
UV
protective coatings
► Glass lenses
are transparent to UVA.
► Besides
glass, most lens materials used on eyewear have a natural
composition that filters out most UV light. Added protection may be
applied to achieve 100% protection from UVA and UVB light.
► UV coating
can be applied to clear lenses, providing 100% UV coating without
any color applied to the lens.
► Added UV
protection may be added with a chemically baked on technique.
However, with technological advances UV protection is most commonly
applied by submerging the lens into a clear chemical agent heated to
approximately 200˚ Fahrenheit for a set time, usually only a few
minutes at most.
► However,
even though a lens has 100% UV protection, the lens cannot filter UV
light that is exposed around the lens. For maximum protection from
UV light, eyewear lens frames that completely cover the eye are
optimum. |
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