METHOD OF DESIGNING FRAMELESS PHOTOCHROMIC SOFT CONTACT LENSES Russian patent published in 2024 - IPC G02C7/04 G02C7/10 G02B5/23 

FIELD: physics.

SUBSTANCE: description relates to a new soft contact lens with frameless photochromic material, in which the geometry of the optical and peripheral regions of the lens is optimized to provide the best cosmetic effect for the eye. Disclosed photochromic ophthalmic soft contact lens comprises: a main portion comprising an optical zone and a peripheral zone adjacent to the optical zone, wherein the optical zone comprises a refractive structure, and one or more of the optical zone and the peripheral zone comprises a photochromic dye; and a diffraction structure located within or adjacent to the optical zone. Ophthalmic lens has a thickness profile which is based on a cosmetic profile associated with a target transmission level (%T). Vision profile associated with the ophthalmic lens is determined based on at least a diffraction structure, and the ophthalmic lens has a ratio of thickness values, defined as the ratio of the thickness of the central portion of the optical zone to the maximum thickness of the peripheral zone, wherein for lenses with positive optical power, the ratio of thickness values is determined based on the thickness of the edge of the optical zone and the maximum thickness of the peripheral zone. Said ratio of thickness values is more than 0.65.

EFFECT: providing the best cosmetic effect by optimizing the thickness profile by limiting the change in the degree of darkness during activation of the photochromic dye.

40 cl, 10 dwg, 1 tbl