by R. M. Ziegler

Created on: October 08, 2008   Last Updated: October 24, 2008

Eyeglasses have existed for centuries. With innovations in modern technology, eyeglasses are more comfortable and attractive while improving vision more than ever. Gone are the thick, Coke bottle style glasses that were considered nerdy.

New frame styles are continually being introduced to the market. Most frames are constructed of metal or plastic, or a combination, with recent introductions of wood and bamboo. Embellishments like rhinestones or multi-colored in-lays have become stylish. If you like the frameless look, rimless styles are available as well. High-end designers like Gucci, Calvin Klein and Oakley have also launched their own frame lines. Designer looks are also available in sturdy, budget-friendly frames.

Improved optics and lens materials make wearing glasses more comfortable while being fashionable. Most eyeglass wearers have myopia, meaning they are nearsighted. Distance vision is blurred. The prescription is indicated with a minus sign as in -4.00. The higher the number, the more nearsighted you are. Minus lenses are thicker on the edges than in the center. The stronger the prescription, the thicker the lenses.

High-index lenses are thinner and lighter than the same prescription made with conventional plastic and are recommended for high minus prescriptions. High-index lenses are able to bend light more than conventional plastic. Indexes range from 1.53 to 1.74. The higher the number, the higher the index, and the end result is a thinner, lighter lens.

Polycarbonate lenses are often confused with high-index lenses. While they are 20% lighter than conventional plastic, they are not necessarily thinner. The main benefit of polycarbonate lenses is that they are impact-resistant, which make them ideal for children or protective eyewear such as sports goggles. One disadvantage is that they do tend to scratch more easily.

When choosing frames, keep in mind that the larger the frame, the thicker the lens edges will be. Plastic frames will camouflage some of the lens edge. In prescriptions -6.00 or higher, rimless styles are not recommended, even with high-index lenses.

People who are farsighted (hyperopia) wear lenses that are convex shaped. The center of the lens is thicker than the edge. Prescriptions are indicated with a plus sign. The higher the number, the stronger the prescription, and the thicker the center of the lens will be.

Aspheric lenses are ideal for strong plus prescriptions. The front surface of the lens flattens, thus eliminating the bulge

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