UVA exposure can damage the retina and lens (of your eye, not your glasses), leading to cataracts and macular degeneration. Compared to non-polarized lenses of equal quality, though, they aren't any more effective at cutting down on UV rays. Many cheap sunglasses have stickers on them saying they block UV.
Moreover, what is the difference between polarized and nonpolarized?
A high quality pair of sunglasses may include polarized lenses. A polarized lens offers the following advantages over non-polarized lenses: Increases visual comfort. Since your eyes aren't constantly challenged by glare, it is easier to view objects in bright conditions.
Is it worth it to get polarized sunglasses?
Not only is glare a nuisance, it impairs depth perception, distorts your view and colors, and can cause temporarily blindness, so the extra cost is worth it for many—especially athletes. Dark tinted glasses block more light than regular sunglasses but they still don't eliminate harsh glare as do polarized lenses.
Why polarized sunglasses are better?
We call this glare and it can impede our vision especially in dangerous or fast moving situations. Polarized glasses come in handy in high glare situations such as light reflecting off of roads, cars, or water. Polarized lenses block those scattering waves of light specifically from horizontal surfaces.