Multifocal contact lens with two sets of focal length zones and movement-sensitive biasing

摘要

A multifocal contact lens has zones 2 having a first focal length and zones 3 having a second focal length. These zones may be radial and relate to near and distance vision. The lens also has an eye movement-sensitive biasing means such as peripheral prismatic area 6 so as to cause the lens to move on the subject's eye in response to movements thereof. Movement of the lens causes a preferred one of the optical zones to be located such that the subject is provided with a desired optical correction to allow viewing at a desired focal length. Zones for distance vision may be at an angle of 45 degrees and zones for near vision at 135 degrees to a horizontal axis.