Multifocal corneal contact lens

摘要

A pair of multifocal contact lenses for a patient comprises a first corneal contact lens having a concave posterior surface and a convex anterior surface. The anterior surface is formed with a power curve having exactly two vision correction zones, namely, a circular distance vision correction zone and an annular intermediate vision correction zone contiguous with the distance vision correction zone. The intermediate vision correction zone of the first lens is concentric or coaxial with the distance vision correction zone. A second corneal contact lens of the pair also has a concave posterior surface and a convex anterior surface. The anterior surface of the second lens is formed with a power curve having exactly two vision correction zones: a circular near vision correction zone and an annular intermediate vision correction zone contiguous with the near vision correction zone. The intermediate vision correction zone of the second lens is concentric or coaxial with the near vision correction zone. The intermediate vision correction zone of the first lens and the distance vision correction zone have optical powers differing in magnitude by less than approximately 1.5 diopters. Similarly, the intermediate vision correction zone of the second lens and the near vision correction zone have optical powers differing in magnitude by less than approximately 1.5 diopters.