All lens materials block some light from passing through the lens. This light reflects back from the lens surface, causing distractions and reducing the clarity of night vision. Conventional glass or plastic lenses reflect about 8 percent of the light that otherwise would reach the eye. High-index lenses reflect up to 50 percent more light than conventional glass or plastic lenses. However, when an anti-reflective lens coating (AR coating) is applied, high-index lenses transmit 99.5 percent of the light. And by allowing more light to enter the eye, AR coatings provide sharper night vision with less glare — a real advantage for night drivers. AR coatings also eliminate lens reflections, they make high-index lenses appear even thinner. This is a big plus if you want to improve your appearance in eyeglasses.