FIELD: medicine; optical system.
SUBSTANCE: intraocular lens comprises an optical portion comprising a front surface, a back surface and an optical axis. At least one of the front surface and the rear surface comprises: a first zone extending from the optical axis to the first radial boundary; and a second zone extending from the first radial boundary to the edge of the optical portion; wherein: first zone comprises an inner portion with a first base curvature and an outer portion with a first base curvature; element providing phase shift divides inner section and outer section. Phase-shifting element comprises a projection with a thickness increased relative to the adjacent parts of the inner and outer sections. Ledge has surface of protrusion with first basic curvature. First stage of phase shifting element extends from inner section to projection surface and second stage of phase shift providing element passes inside from projection surface to outer section.
EFFECT: use of the invention provides controlled variation of phase shifts in light waves passing through different sections of the lens, so as to increase the depth of focus.
8 cl, 1 tbl, 5 dwg
