These fit over sunglasses are especially suitable for driving, motor cycling and most other road users. Copper driver lenses provide sharper contrast, filter blue light and reduce road glare whilst preserving a natural colour balance for comfortable viewing in the day-light. Driver lenses relax the eye muscles to reduce stress whilst driving. Yellow lenses have excellent contrast enhancement and depth perception properties. They're especially effective in flat light or overcast conditions and for night driving helping to increase visibility.