Diffractive multifocal intraocular lens image quality.

The diffractive multifocal intraocular lens is implanted in the eye to replace a cataractous crystalline lens. Axially separated images from two diffraction orders provide near and distance vision. Overall image quality is affected by both the quality of the in-focus component and the energy distribution between images. Modulation transfer function and energy distribution data are presented. Measurement accuracy is limited by the diameter of the point spread function and by the difficulty in separating the focused and defocused components.