Along with Dr Freud, and others, polaroid is good for glare as the reflected light becomes polarized so helps the glare. "blue blockers" (prob a trade name now in general use) are yellow/orange in color, thus taking out the blue light which is not as well focused and contributes to glare and vision distortion. Blue lenses, therefore letting the blue light through, are the worst and shouldn't be used. Relatively speaking, blue light is more energetic than red it is known that damage to the retina (not macular degeneration- different topic) is more likely from blue than other wavelength high intensity light exposure. UV protection to a great extent is marketing hype but: Most UV is absorbed and filtered by the cornea=snow blindness=sun burn of the cornea etc. Some is filtered by the lens and has been shown to add to tendency for cataract formation. Studies on the Chesapeake Bay watermen and others have proved that but the surgery rate in the watermen was not greatly different that the controls on the beach. Different types of cataract contribute to the difference. Little UV gets to the retina and there is no good evidence that UV or even light at all (bit more likely and some suggestion is there) contributes to macular degeneration. However!! If you are going to wear sun glasses for comfort, especially on the salt, beach, skiing etc as most of us do, they should filter UV as the exposure in those settings is high (altitude, reflected doses etc) and your pupil will dilate behind a dark lens letting in considerably more UV than if you don't wear the glasses at all. That is, from a UV (not visible light which is what seems "bright" and for which we wear the sun glasses in first place) standpoint, you are better off without any than with non UV filtering sun glasses. Many clear prescription plastic lenses and all glass (rarely used these days due to weight and other considerations) naturally filter some UV. Besides, squinting in bright light causes wrinkles. My opinion cheap ones work as well as expensive, pay your money take your choice. Support the vendors on the salt. Color of lens other than as noted above is little consequence. More fashion, though a neutral gray does not cause a color perception shift the way colored lenses will. You quickly get used to that. I found looking at fall foliage really is more spectacular through glare control (Corning glass, orange "blue blocker" type lenses). YMMV
