NON-PROGRESSIVE CORRIDOR BI-FOCAL LENS WITH SUBSTANTIALLY TANGENT BOUNDARY OF NEAR AND DISTAL VISUAL FIELDS Russian patent published in 2018 - IPC G02C7/06 

FIELD: optics.

SUBSTANCE: bifocal non-progressive ophthalmic lens comprises a convex surface and a concave surface that comprises a first vision field with a first optical power for distance vision and a second field of vision with a second optical power for near vision. First and second fields of vision contact each other in a substantially tangent manner, without a segment and without a progression corridor, and smoothly blending with the remainder of the concave surface. Respective radii of the first and second fields of vision converge at respective first and second contact points in which the first and second vision fields are connected in a substantially tangent manner through the contact surface also contained in the concave surface of the lens.

EFFECT: technical result is to provide a smooth transition between the fields of distance and near vision with no noticeable progressive force, a separation line, a jumping image or other optical distortions.

5 cl, 5 dwg