These glasses have excellent clarity and optical properties and block UV exceptionally well. This alone makes your eyesight improve about 30%. It makes you see clearer as well. The polarizing filter effectively reduces glare and sun reflection off smooth surfaces. The only problem with the sunglasses is they do scratch easily. You must NEVER rub them with anything, and clean under a faucet with running water and soapy fingers. They last well if you do this. They fit well over your prescription glasses, and are very comfortable. They cover the sides and top very well, but could be a little better if the sides had larger portholes to see better in your peripheral vision. For 20 bucks, they can't be beat! I Mean it!!!