Description Ray Ban B-15 indicates that the glasses are brown lens. There are also lenses gray-green color G-15. In any case, both these lenses provide a 100% UV blocking. Only sunglasses with brown lenses, offer a little more contrast, as the output has more colors of blue spectrum as opposed to gray or gray-green.
Leading ophthalmologists recommend wearing the lens of the natural "natural" colors, including brown B-15XLT. More recently, scientists have found that wearing glasses with lenses Brown contributes to the development of happiness hormone in the body (serotonin). Indeed brown lens color makes any picture over the rainbow, and consequently improves the mood.
Brown lenses are considered to be sufficiently versatile and suitable for any weather.