Design of aspheric intraocular lenses.

The value of aspherizing intraocular lens surfaces for the purpose of improving retinal image quality of pseudophakic eyes was investigated. Surfaces were made as conicoids. Changes in primary wave aberrations and refractive errors were found to be proportional to changes in surface asphericity. The optimum asphericity depends markedly on ocular parameters, lens fitting position and how well lenses are centred within the eye. If lenses are not well centred, the asphericity that eliminates spherical aberration may result in poorer performance than that occurring with spherical surfaces. It is suggested that there is no general benefit in aspherizing surfaces of intraocular lenses.