Contact Lenses

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The Issue

Contact lenses are medical devices which, like drugs, provide benefits while posing certain risks. If you wear contact lenses, you should take steps to minimize these risks and protect your vision.

Background

Many people wear contact lenses to correct their vision. The reasons for choosing contacts over glasses or refractive eye surgery (which corrects the shape of the cornea) include lifestyle, sports and appearance.

Contact lenses are tiny saucer-shaped pieces of plastic. They are placed on the cornea of the eye, and float on a thin layer of tear fluid. In some cases, contact lenses may offer improved vision correction when compared to glasses because they correct the refractive error closer to the eye. Several types of contact lenses are available.

Hard lenses are made of a firm polymer plastic material. They are easier to keep clean because they are less likely to absorb foreign material from the eye or environment. You must remove hard lenses before you go to sleep because they restrict the flow of oxygen to the cornea, which needs oxygen to stay healthy.

Soft lenses are less durable, but are more comfortable because they are made of a softer plastic called hydrogel. Because they contain a higher percentage of water, they per