Protection From UV radiation

"Ultraviolet radiation reaches the eyes not only from the sky above but also by reflection from the ground, especially water, snow, sand and other bright surfaces. Protection from sunlight can be obtained by using both a brimmed hat or cap and UV absorbing eyewear.

A wide-brimmed hat or cap will block roughly 50 per cent of UV radiation and reduces UV that may enter above or around the glasses. Ultraviolet absorbing eyewear provides the greatest measure of UV protection.

It is prudent to protect the eyes of children against UV radiation by wearing a brimmed hat or cap and sunglasses. Sunglasses for children should have lenses made of plastic rather than glass for added impact protection.

Ideally, all types of eyewear including prescription spectacles, contact lenses and intraocular lens implants should absorb the entire UV spectrum (UV-A and UV-B). UV absorption can be incorporated into nearly all optical materials currently in use, its inexpensive, and does not interfere with vision. The degree of UV protection is not related to price. Polarisation or photosensitive darkening are additional sunglass features that are useful for certain visual situations, at the same time providing UV protection.

For outdoor use in the bright sun, sunglasses that absorb 99-100 per cent of the full UV spectrum to 400 nm are recommended. Additional protection for the retina can be provided by lenses that reduce the transmission of violet/blue light.

Such lenses should not be so coloured as to affect perception of the colour of objects, such as traffic signals. The visible spectrum should be reduced to a comfortable level to eliminate glare and squinting. Individuals who also wear clear prescription eyewear outdoors should consider using lenses which absorb 99-100 per cent of the UV radiation to 380-400 nm."