Gray lenses eliminate nearly all glare. They reduce more sun glare than any other known technology. If sun glare reduction is your primary need, non-polarized Gray Extreme Glare Sunglasses' lenses are the best available option for this purpose.
Gray lenses eliminate reflective glare very effectively, but in comparison to Rose Lenses, they are more difficult to see with when viewing things below the water line, because darkness impedes vision in almost all circumstances.