•  Glasses - consist of a frame and two lenses that work like magnifying glasses. The amount of curvature determines exactly how much the lenses magnify. For farsightedness (hyperopia), a convex lens is used. For nearsightedness (myopia), a concave lens is used. A convex lens curves outward on both sides, and the concave lens curves inward on both sides.

• Plastic Lenses - are half the weight of glass lenses.  They are more easily scratched than glass lenses, but an extra coat of tough quartz can be applied to protect the surface.  They are also more impact-resistant than glass.  Plastic lenses are best for low prescriptions nearsighted power of less than -300, farsighted less than +300.

• Glass Lenses - are heavy, expensive, and are the least safe of all lenses.  Glass lenses are rarely prescribed now because lighter, more durable material is now available.

•  Hi-Index Lenses - bend light differently so that stronger corrections can be thinner and lighter in weight.  Glass lenses are also available with the slimming advantages of High Index, yet weight continues to be a problem.  Plastic lenses with High index are usually thinner, so they tend to be even more lightweight.  High Index lenses absorb all harmful UV (ultraviolet) light and can be tinted to any shades or colors.

•  Polycarbonate Lenses- are the most impact resistant lenses, and therefore are the common choice for young people and those who are active.  They are usually the most comfortable lenses.  They absorb all harmful UV light and can be made with extra thin edges because of their strength.
•  EXTRA INFORMATION -

        - Scratch Protection - a tough coat of quartz that protects the surface of plastic and polycarbonate lenses.

        - UV Protection - can be added to lenses to absorb all harmful UV light.  UV protection usually comes with most prescriptions.

        - Tints - lenses can be colored in a variety of colors, each having a specific purpose.