Abstract

Current diffractive bifocal contact lenses use surface relief variations over the diffractive zone to create relative phase delays giving a focusing effect.^{1, 2} To achieve the required phase delay the junctions in the diffractive zone must be about 1 to 4 µ m in height depending on the lens material.^{3, 4} Surface relief shape will influence the amount of light in the different diffractive foci.^{5, 6} For example, as the diffractive zone height increases more light will be found in the first order (near) focus.

© 1995 Optical Society of America