Double aspheric lenses are a new type of lens which has recently become available on the market. They have the same principal as aspheric lenses; the lens is flatter and thinner, but they are doubly so. Normal aspheric lenses are only aspheric on the outer surface, but double aspheric lenses are aspheric on both sides of the lens. This gives you an even more lightweight version of eyewear than do aspheric lenses. Also, due to the lens being 10% flatter and thinner than conventional aspheric lenses with the same power, distortion of your appearance is kept to an absolute minimum.
With traditional lenses, or normal aspheric lenses, image distortion can occur when you try to focus on something through the edges of your lenses. Another advantage of double aspheric lenses is that they have an exceptionally large focal point area, and are spherically designed in the centre of the lens. This means that a much larger area shows a non distorted image, giving you a high quality of vision that you would naturally have.
Many double aspheric lenses are coated with an anti reflective covering, which is very useful and important, as the nature of the lenses means they reflect more light than normal lenses. This can be very distracting, and even dangerous whilst driving. Coating the lenses eliminates this problem, and also protects them from scratches and damage, and protects your eyes from harmful UV rays.