High index lens materials are lighter in weight and thinner than their regular glass or plastic counterparts. The benefit is that if you have a strong prescription, you are no longer forced into unsightly Coke-bottle lenses. Just about everyone can get attractive eyeglass lenses that complement their appearance, rather than detracting from it. Different manufacturers make different high index lenses, and what sets each lens apart from the others is its index of refraction. The higher the IOR, the denser the material. All things being equal, a 1.66 IOR material will result in a thinner and lighter-weight lens than a 1.57 IOR material will.

No other lens material can be safely processed as thin as polycarbonate. Combining polycarbonate's high index properties with this unique feature means your new polycarbonate lenses will be thinner than any other lens. You know you are wearing the slimmest, most attractive lenses possible when you order polycarbonate. Polycarbonate lenses are the best investment you can make when ordering new eyewear. The same material used in polycarbonate lenses is found in helmet visors worn by astronauts during space travel and shields carried by riot police. The exceptional protection provided by polycarbonate lenses has made these tough lenses the only choice for children's eyewear. With the active lifestyle enjoyed by many adults today, wearing lenses made of polycarbonate adds a comforting margin of protection for your precious eyes.

Transitions lenses are available for nearly every lens design, refractive index and prescription. Performance features include advanced variable-tint technology that allows rapid darkening when you go outside (and rapid return to clear when you go in), and 100% UV protection. They come in regular, lightweight plastic materials as well as in high-index plastic and polycarbonate, the thinnest and lightest lens material available. They have a front-surface coating that changes color (to gray or brown) when exposed to ultraviolet light. The changeable coating means that the color darkens evenly regardless of lens prescription or thickness.