Lens Materials: Thin and Light

Aspheric Lenses

High prescription lenses, both near and farsighted, tend to be thick and have reduced optical qualities further from the center of the lens. Aspheric lenses minimize thickness while improving optics of a lens. It will thin down the edges of a highly nearsighted lens or reduce the overall thickness and magnification ("bug eye effect") of a high plus/farsighted lens.

High Index Lenses

High index lenses are thinner and lighter than regular plastic (CR39) lenses. "Index" means "index of refraction", which is how quickly a substrate bends light rays when it enters the lens. The higher the index, the less material it takes to bend light and the thinner the lens. True high index lenses have good optics and can make lenses very thin.

High Index and Aspheric

Combining both benefits of high index and aspheric design give you the ultimate thin lens with superior optics. We use Essilor's Thin&Lite lenses: High-index lenses have flatter curves for a reduced lens profile. A flatter curve can cause blurred vision. This is why Thin&Lite incorporates a proven aspheric design into the lens to vastly improve optics. Thin&Lite provides the most advanced optical performance, while preserving cosmetic appearance. In addition, higher refractive index bends more light - so Thin&Lite lenses are much thinner and lighter than standard plastic lenses. Thin&Lite lenses are 100% UVA and UVB protection.

A higher refractive index increases the amount of reflection on your lenses. Crizal coating is the premier anti-glare treatment with the best technology and performance - unmatched durability and scratch resistance, with unparalleled cleanability and smudge resistance. These anti-glare coatings can make your high index lens transmit nearly 100% of light, versus 80% - 85% uncoated.

Polycarbonate: Thin, light and Safe

Polycarbonate is a shatter resistant material that is 12 times stronger than regular plastic (CR39) lenses. It is used in aerospace extensively, such as for visors for NASA astronauts. It is also a high index material and is thinner and lighter than CR39. For very high prescriptions it may not be "thin enough" and the optics are not as good as a specialized high index material.

Trivex is a newer material used by the military for shatter resistance. It is even tougher than polycarbonate but is not used as much because it is almost as thick as regular CR39 lenses. But if you are planning on joining the bomb squad, then maybe it's time to ask for Trivex lenses!

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