Recently a variety of colored contacts have been introduced. These fall into three major categories.
• VISIBILITY TINTS
These lenses have a very slight tint (usually blue ) that makes it easier to visualize them in a lens case or when handling them for cleaning. This tint is not visible when worn and does not change the color of the eye.
• ENHANCER TINTS
These colors are designed to work with light colored eyes such as blue or green. The tint will work with the eye’s natural color to intensify or alter the perceived color. The overall effect can be very natural since the underlying iris color and pattern does not have to be covered up. These tints will not work for dark eyes.
• OPAQUE TINTS
This type of lens can completely alter the color of any eye, light or dark. The surface of the lens is treated with an opaque color placed in a pattern, which mimics the normal structure of the iris. Because none of the eye’s natural color shows through, the eye will take on the color of the lens. This feature is the great attraction of opaque lenses. The drawback is that in some eyes the effect does not appear completely natural.
Colored lenses are available as daily and extended wear, disposable and planned replacement lenses. However all colors and patterns are not made in each style. Colors for astigmatism are more limited and presbyopia is not yet available. Colored lenses may be worn even if no visual correction is needed ( no optical power in the lens. ).