The public is often advised by medical experts of the importance of wearing sunglasses in order to protect the eyes from UV*, radiation and excessive light exposure. Excessive exposure to ultraviolet radiation (UV) can cause short-term and long-term ocular problems such as photokeratitis, snow blindness, cataracts, pterygium, and various forms of eye cancer*.
The National Eye Institute also recommends sunglasses to help prevent or delay cataracts, in spite of the little research available so far to support the idea.
“While sunglasses’ role in cataract prevention may be unclear, they should be worn to protect your eyes against macular degeneration and other conditions worsened by too much exposure to ultraviolet rays. If there’s enough sun to get a tan, you should wear sunglasses,” says Dr. Roberts of the National Eye Institute.
Similar approach is conveyed by David D. Richardson, M.D., Medical Director-San Gabriel Valley Eye Associates, Inc.:
“I tell all of my patients to wear quality sunglasses with ultraviolet protection. Although we do not have conclusive proof that wearing sunglasses can delay the progression of cataracts, there is substantial laboratory and population-based evidence to support the association of UV exposure with progression of both cataracts and macular degeneration.”
Although no one can quantify the correlation between excessive UV and light exposure to vision problems, all ECP are in agreement that this correlation does exist.
It is important to purchase quality sunglasses as those are the only ones that I would trust to actually have a UV filter.
The implied from the statement above is that low quality sunglasses without broad spectrum UV protection will reduce light transmission to the eye causing pupil dilation and thus actually increasing exposure of inner eye structures to UV radiation, increasing possible damage.
Summary and Recommendations
Eye care practitioners should explain these facts when prescribing protective eyewear to the patient.
More considerations to share with your patients:
Some lens materials (e.g. glass polycarbonate and several HI index materials are natural UV filters and others) especially acetate lenses used in un expensive sunglasses need additional UV coating.
Coating the back side of sun lenses with AR coating reduces annoying glare and increases sharpness of the objects in reduced light environment and thus reduces strain on the eyes.
Other qualities of protective eyewear depend greatly on the type of usage for example for some patients (fishing outdoors activities) polarized sun lenses could be very helpful for the others quite dangerous (pilots, downslide skiers) changing depth perception.
Cancer Council Australia; Centre for Eye Research Australia: Position Statement: Eye Protection. August 2006