WHAT ARE FRESNEL PRISMS?

Fresnel prisms are wafer-thin, transparent sheets of adhesive plastic.

One side is fixed to the lens of the wearer's glasses, while the other has special grooves that alter the way light enters the eye.

The prisms, the strength of which can be adjusted depending on the patient's needs, are often used to treat double vision.

The stick-on panels may be worn for several months. If they prove particularly successful, patients can have glasses made with built-in prisms.

Double vision can occur in one or both eyes. It can be caused by an irregularly shaped cornea or abnormalities of the cornea, dry eye, or abnormalities of the lens or retina.

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