Sunglasses can help protect your eyes from ultraviolet (UV) rays, which can contribute to the development of cataracts and macular degeneration. The Mayo Clinic suggests that you choose sunglasses that block 99% to 100% of UVA and UVB rays, screen out 75% to 90% of visible light, have lenses that are perfectly matched in color, and do not have distortions or imperfections in the lenses.

Mayo Clinic, July 2019