Sunglasses Rope Adjustable Holder Sport Strap Eyeglass Cord

Sunglasses can block uncomfortable glare while protecting the eyes from ultraviolet rays.All thanks to metal powder filters, which "select" light as it enters.Tinted glasses selectively absorb some of the wavelengths that make up the sun's rays because they use very fine powders of metal (iron, copper, nickel, etc.).In fact, when light hits the lens, it is subtracted by a process called destructive interference.That is, when certain wavelengths of light (uva, uvb, and sometimes infrared) pass through the lens, they cancel each other out on the inside of the lens, toward the eye.It is the fashionable variety of sunshade mirror actually, although the blocking effect to sunshine should be less than sunshade mirror, but its fundamental purpose is to have adornment effect.Tawny sunglasses are recognized as the best lens color in sunglasses products. They can absorb almost 100% of ultraviolet and infrared rays.And downy tonal make vision comfortable, let an eye not easy fatigue.Glass lens has excellent optical properties and is the best optical material.But the ordinary glass lens is easy to break, impact resistance is relatively weak, safety is not high.