NoIR filters can help people minimize eye discomfort and maximize visual resolution. Filter shade number 40 ‚Äì amber ‚Äì allows in 16% of visible light, has 100% ultraviolet protection and is an all purpose color which heightens contrast and relieves glare. It also offers blue blocker protection. The standard fit-over style frame may be worn over most prescription frames or worn alone. It features side shields with temple lapped construction to keep out extraneous light and wind and it has curved temple pieces for a non-slip fit. Frame measures 6 1/4″ temple to temple.