Protecting the Eyes: UV Light
Decreasing light levels with a tint may give a greater level of visual comfort, but may not offer enough protection against wavelengths of light known to be harmful to the sensitive tissues of the eye. Specifically, protection from the high energy, damaging, short wavelength UV light. Lens materials such as plastic and poly carbonate have…
Decreasing light levels with a tint may give a greater level of visual comfort, but may not offer enough protection against wavelengths of light known to be harmful to the sensitive tissues of the eye. Specifically, protection from the high energy, damaging, short wavelength UV light. Lens materials such as plastic and poly carbonate have some UV absorbing capability (see Lens Materials).
For added protection from UV light, sunglasses should have UV light absorbing properties that eliminate the damaging light rays from reaching the eyes. Look for ‘100% UV protection’ or ‘UV 400’ labeling on a tag or lens sticker.
For regular eyeglasses, a UV coating can be applied (see Lens Technology). Regular clear plastic prescription eye wear, a plastic called CR-39, does provide some UV protection. A UV coating takes it a step further to 100% UV protection. Poly carbonate, which is known as safety ‘impact resistant’ plastic, does not need an additional UV coating for 100% UV protection.
Keep in mind: sunglass lenses that are labeled as polarized does not mean UV protection. This is a feature added to lenses to decrease glare and increase visual comfort.
