You should already know that the best way to protect your eyes from the sun’s damaging ultraviolet (UV) rays is to wear sunglasses when outside, but just how much UV protection do you need?

The answer lies within the numbered rating, and the highest UV protection rating offered is UV 400.

According to the American Academy of Ophthalmology, you should choose sunglasses that block 99% to 100% of UVA and UVB rays, and UV 400-protected sunglasses do this.