Ultraviolet "UV" protection and UV coatings are an important consideration when buying eyeglass lenses. Most eyeglass lens materials already have 100% UV protection, and this list includes polycarbonate lenses, high index lenses, Trivex lenses, Transition lenses, and polarized lenses. Eyeglass lenses that do not have UV protection are the least expensive CR-39 lenses, and it is important to add a UV coating to these lenses, especially if the glasses will be worn outside.
Most importantly, sunglass lenses that are CR-39 must also have UV protection in the form of UV coating and this is an FDA regulation. Cheap flea market sunglasses often do not have UV protection or UV coatings; this is most dangerous because the tint causes the pupils to dilate, and then the eyes admit more UV radiation. UV Protection and UV coatings in eyeglass lenses have come to the forefront recently, as Prevent Blindness America (PBA) has declared May 2009 as “UV Awareness Month” to help educate the public on how to protect their eyes.
Ultraviolet rays are well known for their damaging effects on the skin, PBA points out, but exposure to UV rays can cause “sunburns” to the eye, also known as photokeratitis. The damaging effects of UV rays may not develop until years later. In fact, UV damage is cumulative and has been linked to cataracts and macular degeneration later in life. The delicate skin around the eye and the eyelids is also susceptible to UV damage.
UV protection and UV coatings in eyeglasses and eyeglass lenses are strongly recommended. PBA notes that no matter what time of year it is or what the weather forecast is, sunglasses that block 100 percent of UV-A and UV-B rays should always be worn in conjunction with a brimmed hat. Wrap-around sunglasses are best as they protect the eyes and the skin around the eyes. Some contact lenses may offer UV protection but they can’t protect the entire eye and the skin around it.