A contact lens design effective in correcting a stigma tism.

A prescription lens to correct the eye's vision. ertex of Surface (or the Pole).  The point on the surface of a lens where the optical axis enters the surface.  For a convex surface, for example, it is the highest point on the surface.

A contact lens design effective in correcting astigmatism.

a lens with two different optical powers at right angles to each other for the correction of astigmatism.

Used to correct astigmatism, a lens containing a cylindrical (or out-of-round) surface. A toric surface is ground with two different curves at right angles to each other with the weaker of the two curves located on the cylinder's axis. Go to Top

A curved lens on which one of the surfaces has two powers worked in order to correct astigmatism.

Refers to any cylindrical lens having a base curve other than zero (flat).