CENTRAL OPTICAL ZONE OF INCREASED STIFFNESS IN SOFT CONTACT LENSES FOR ASTIGMATISM CORRECTION Russian patent published in 2020 - IPC G02B1/04 G02C7/04 

FIELD: medicine.

SUBSTANCE: invention relates to ophthalmic devices comprising a contact lens having increased stiffness in the central optical zone as compared to the peripheral zone. Disclosed is an ophthalmic device comprising a contact lens in which material of the central optical area is formed from a reaction mixture containing at least one N-alkyl methacrylamide and at least one silicone-containing component. Also presented is a method for preparing said ophthalmic device. Optical zone with a higher modulus of elasticity forms a bulge above the corneal surface thus allowing a lachrymal lens to form. Lachrymal lens repeats or takes the shape of the curvilinear surface of the contact lens. Combination of lachrymal lens and optical zone provides optical element for correction of abnormality of refraction.

EFFECT: technical result is proposed ophthalmic device enables to correct astigmatism.

40 cl, 2 dwg, 14 tbl, 54 ex