It turns out that there are many different things that you can do with two pieces of glass, and these things can have a big effect on you when you use the lenses. As you will see in this article, there really is a difference.
Good sunglasses can eliminate UV rays completely.
Sunglasses provide protection from intense light - When the eye receives too much light, it naturally closes the iris. Once it has closed the iris as far as it can, the next step is squinting. If there is still too much light, as there can be when sunlight is reflecting off of snow, the result is damage to the retina. Good sunglasses can block light entering the eyes by as much as 97 percent to avoid damage. Sunglasses provide protection from glare - Certain surfaces like water can reflect a great deal of light, and the bright spots can be distracting or they can hide objects.