METHOD FOR DESIGNING NONCIRCULAR SOFT CONTACT LENS Russian patent published in 2016 - IPC A61F9/00 G02C7/04 

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine. A method for designing noncircular soft contact lenses to improve lens stability, rotation and alignment in an eye comprises: determining an upper eyelid geometry; determining a patient's eye surface geometry; setting an initial geometric shape of an outer contour of the noncircular contact lens; calculating a first area of an overlap of the upper eyelid and an upper part of the noncircular contact lens when the noncircular soft contact lens is placed in optimum final position in the eye as determined by the eye surface geometry; calculating a second area of an overlap of the upper eyelid and the upper part of the noncircular contact lens when the noncircular contact lens is in the least optimum position in the eye as determined by the eye surface geometry; and providing a maximum difference between the first and second areas of the overlap by varying the geometric shape of the outer contour of the noncircular contact lens. In another version, the method involves determining lower eyelid geometry, whereas the area to be determined is found between the lower eyelid and a lower part of the noncircular contact lens. In one more version, the method involves determining upper and lower eyelid geometry, and the area to be determined lies between the upper eyelid and the upper part of the contact lens and the lower eyelid and the lower part of the noncircular contact lens.

EFFECT: using this group of inventions is expected to optimise the outer contour of the contact lens to reach the maximum difference in 'lens-eyelid' contact zone in two opposite positions of the contact lens.

26 cl, 8 dwg, 2 tbl, 3 ex