High-index and aspheric lenses

"If you need high-powered lenses you can improve the weight or appearance of your glasses with special lens materials and designs. High-index lens materials and aspheric designs mean that lenses can now be made thinner, lighter and better looking than traditional lens types. High-index materials and aspheric lens design make lenses for short sight and long sight thinner and allows more optimal vision through the lens area away from the centre of the lens"