Varifocal optics for a novel accommodative intraocular lens

摘要

The development of adaptive optics for the human eye to correct aberrations, to restore accommodation after lens extraction due to cataract and to correct age-related presbyopia have interest of academia and industry. We report on optics for a new accommodative intraocular lens which uses a two-element varifocal Alvarez lens. This lens has two refractive elements with cubic surfaces which, in combination, form a varifocal lens when the elements are shifted relatively to each other perpendicular to the optical path. The accommodative function of the lens will be driven by the ocular ciliary muscle. The refractive elements of the dual-optic intraocular lens are designed to provide a near emmetropic on-axis vision with a > 4 dioptre accommodation range. The anterior element has a spherical lens to correct for the overall refraction of the eye, aspheric terms to correct the corneal asphericity and a cubic term as accommodative component; the posterior element has a cubic shaped surface only. The modular transfer function shows that the image on the retina reaches a diffraction limited performance for the on-axis vision in combination with the aspheric correction for aberrations of the cornea. We conclude that the varifocal lens is uniquely suitable for application as an intraocular accommodative lens because of its optical quality and ample accommodative power.