UV protection of the eye is of utmost importance. UV radiation from the sun can damage not only the skin of your eyelids, but also the cornea and lens in addition to other parts of the eye. UV exposure contributes to the development of certain types of cataracts, growths on the eye and possibly macular degeneration. Sunglasses should block 99-100% of both UVA and UVB rays.
UV radiation is present not only when the sun is shining but in the shade too. Even a cloudy day will produce harmful UV rays which can be as high as 70-75%. So sunglasses are highly recommended even if the sun isn’t bright. The actual color and degree of darkness of a sunglass is irrelevant to its ability to block UV rays.
Children are particularly sensitive to UV rays affecting their eyes. By the time they are 20 years old they have already been exposed to approximately half the amount of UV radiation a 60 year old has been exposed to. So the earlier you start to protect your eyes, the better off you’ll be.
Polarized VS UV Protected Sunglasses:
There are two distinctive types of protection that your sunglasses need to have whenever you are outdoors. The most crucial is the UV protection from the harmful rays of the sun. The second is the elimination of glare provided by a polarized lens. Polarization provides a better image clarity-the ability to see, for example, through a glary windshield or see through a body of water when the sun is reflecting off the water. This allows for enhanced contrast and depth perception. Also with polarization colors appear more vibrant and brighter and generally helps to reduce eye strain. The one caveat is that not all polarized lenses provide 100% UV, but only adequate UV protection. Check with your sunglass provider if your choice of sunglass has 100% UV protection.
The downside to wearing polarized sunglasses is that they can black out or even severely reduce or skew the visibility of LCD screens which is basically most digital devices. However, this writer believes that the benefits do outweigh this one disadvantage.
In general think of UV protected sunglasses as sunscreen for the eyes.