The sunglasses you have your eyes on might be groovy but if they don't guard your eyes from the sun's rays, they're best left on the shelf.
It's a scientific fact that ultraviolet (UV) rays are harmful to your eye, potentially causing cataracts, macular degeneration, and even cancer of the eye. There's no question that protecting your eyes from exposure to UV is imperative. You need lenses that meet certain standards, bottom line.
These days, sunglasses don't always come with a visible protective coating. Sometimes the UV protection is formulated into the lenses which makes it tricky to tell if they provide protection. But how do you know if your new pair of sunglasses offer UV protection? You can always test your shades the old-fashioned way and look at the sun to check them. If you're not into that, however, there are some easier methods to make sure your sunglasses offer UV protection.
What Is UV Light Protection?
In general, the shorter the wavelength of light a source has, the more dangerous it is to living things. Ultraviolet light is a type of electromagnetic radiation that has a wavelength ranging from 10 to 400 nm. While it is shorter than visible light, it's longer than the light that comes from an X-ray. Ten percent of the sun's total electromagnetic radiation is found in UV light.
There are two kinds of UV light - UVA and UVB. Although both UVA and UVB can cause damage to your skin and eyes, UVA wavelengths are longer and are therefore less dangerous. The sun s harmful UVB rays are the ones that are attributed to cancer of the eyes and macular degeneration. It is especially vital to guard your eyeballs against the UVB rays but protection for UVA rays too is actually important as well.
UV protection is the act of blocking the sun s harmful UV light. Sunscreen is designed to shield your skin from UV rays. When it comes to protecting the eyes, the feat is typically attained through wearing a pair of sunglasses that stop the sun's UV rays and glare from reaching your eyes. In order to be ultra-effective, sunglasses must block out both UVA and UVB rays.
Degrees of UV Protection
Just because a pair of sunglasses advertise they protect you from UV radiation does not mean they offer both UV A and B blocking. Neither does the claim indicate the degree they protect your eye from exposure to the sun. So, the old pair of sunglasses you just stumbled onto may not be as UV protected as you think.