For your eyes only.

Quality lenses are highly recommended for best comfort and vision — both in regular glasses and sunglasses. They should protect your eyes from ultraviolet (UV) rays that may contribute to causing cataracts, macular degeneration and other diseases.

Here are some tips for purchase of sunglasses and regular glasses.

1. Blue-blocking plastic lenses. Often promoted for sun protection, blue-blocking lenses also block red, amber and blue light — which makes it difficult to discriminate traffic light colors. They make the surroundings look yellow or orange. The tint makes distant object appear clearer, especially in snow and haze. These are good for skiers, hunters, boaters and pilots.
   
2. Polarized lenses. Although polarized lenses protect against glare, they don't meet the criteria for UV protection unless they have additional UV-blocking material in the lenses. They are useful for fishermen or people that do a lot of driving, though many outdoors people prefer polarized sun lenses. These lenses cut out light from one whole meridian, typically the horizontal one. This minimizes the glare from light that bounces off water, the hood of your car, or a shiny road surface.
3. Photochromic lenses. Photochromic lenses change from light to dark depending on the amount of ultraviolet light they are exposed to. This type of lens protects the eyes from glare, sun and UV radiation while also maintaining visual acuity. Also, photochromic lenses do not distort color.
4. Polycarbonate lenses. Polycarbonate lenses hold up better under impact. A wise choice for children and athletes, as polycarbonate lenses shield the eyes from UV radiation as well as protect the eyes against impact injuries that may be sustained during play and sports.

There are also sunglass clips that fit your frames. These can be very effective in protecting your eyes if they are of good quality.