Schering Corporation

Wesley-Jessen Corporation

Malcolm G Townsley

Samuel Loshaek

A contact lens for correcting astigmatism. The front surface has a central optical zone and an outer carrier having two points of maximum thickness located at an oblique angle of about 110.degree. to 130.degree. as measured from the vertical axis of the lens. The anterior surface of the lens is symmetrical about its vertical axis. The carrier tapers from the points of maximum thickness to thin portions at the top and bottom of the lens. The rear surface of the lens has an outer spherical base curve zone, an inner toric zone, and an intermediate transition zone having thickness that gradually increase from the base curve zone to the toric zone. By making the radius of the base curve zone substantially equal to that of the toric zone's major meridian, a thinner, more comfortable lens is obtained.

Contact lens for correction of astigmatism

Hydrophilic bifocal corneal contact lenses of the alternating-vision type having a critical set of dimensions for the various elements which results in a surprising increase in the success rate of persons wearing these improved lenses.

Hydrophilic bifocal contact lens

A process for prescribing and manufacturing contact lenses wherein a first concave curvature is developed on the interior face of the lens in the central optical zone. This concave curvature conforms to a portion of a sphere having a radius equal to the radius of a base curve determined to be suitable for the particular patient. A second concave curvature is developed on the interior face of the lens to provide a bearing zone in surrounding relationship relative to the optical zone. The second curvature conforms to an annulus of a sphere having a radius determined by the slope of the patient's eye at points of contact of the second curvature with the eye. The slope is determined by calculating the eccentricity of the ellipsoidal surface which most closely describes the shape of the patient's eye.

Growing community of inventors

Park Ridge, IL, United States of America

Malcolm G Townsley