INTRAOCULAR DIFFRACTION LENS Russian patent published in 2002 - IPC

FIELD: ophthalmologic optics; artificial lenses for eyes. SUBSTANCE: lens is made of biocompatible flexible or hard material, type PMMA. It is, essentially, thin plate one of whose surfaces bears microrelief in the form of annular diffraction grating with luminous profile. Desired optical intensity of intraocular lens is ensured due to phenomena of light diffraction on structural surface. Maximal depth of microrelief profile is equal on entire surface of lens. Its absolute value h_max≫λ_o and amounts to several wavelengths of visible part of spectrum. Diffraction lens has equal optical intensity for at least two wavelengths of visible range of spectrum, that is, it is achromatic or apochromatic. In addition lens is split into even number of sectors having different optical intensities or it is aligned with annular diffraction grating at constant spacing to expand pseudo-accommodation of eye. This expansion makes up 0 to 4 diopters. In order to obtain broken optical axis and to project image onto paramacular part of retina (in case of defective macula) diffraction lens is built integral with linear diffraction grating. Cornea aberration is compensated for. Lens can be implanted through small incision which will essentially reduce post- operation astigmatism of cornea. Intraocular lenses may be manufactured using advanced methods of laser technology. Lens photomatrix is synthesized and replicated by way of stamping. EFFECT: enhanced visual activity of eye with implanted lens; reduced cost of artificial lens. 5 cl, 6 dwg