Bifocal contact lens
AssigneeVistakon, Inc.
InventorCharles A. Bayshore
Life of this patent
Estimating the term…
Abstract
A soft, multifocal contact lens of the segmented type intended to translate vertically between the near-vision and distance-vision modes, characterized in that the superior portion of the lens is equiangularly truncated from points on either side of the vertical axis at the apex of the lens to points on each respective side proximal the horizontal axis of the lens.
Claims27
A multifocal contact lens comprising a lens body with a generally spherical, concave inner surface adapted to fit the cornea of a numan eye, and a generally convex outer surface;
- said lens body having a central, horizontal axis defining a superior portion of the lens and an inferior portion;
- said lens body having a central vertical axis which, at the point of intersection with said horizontal axis, defines the geometric center of the lens;
- the superior portion of said lens body being substantially equiangularly truncated from points on either side of the vertical axis at the apex of the lens to points on each respective side proximal the horizontal axis;
- the inferior portion of said lens body being defined by an arc of substantially uniform radius from the geometric center of the lens over a major portion of the perimeter thereof;
- said lens including a first optical zone having at lease a major portion thereof in the superior portion of the lens;
- said lens including a second optical zone having at least a major portion thereof in the inferior portion of the lens;
- the focal length of said second optical zone being shorter than that of said first optical zone.
A multifocal contact lens comprising a lens body with a generally spherical, concave inner surface adapted to fit the cornea of a human eye, and a generally convex outer surface;
- said lens body having a central, horizontal axis defining a superior portion of the lens and an inferior portion;
- said lens body having a central vertical axis and being symmetrical thereabout, the intersection of said vertical and horizontal axis defining the geometric center of the lens;
- the superior portion of said lens body being substantially equiangularly truncated from points at the apex of the lens spaced apart from about 3 to 5 mm to points on each respective side of the lens proximal the horizontal axis, the included angle of truncation being from about 65 to 80 degrees;
- the inferior portion of said lens body being defined by an arc of substantially uniform radius from the geometric center of the lens over a major portion of the perimeter thereof;
- said lens including a first optical zone having at least a major portion thereof in the superior portion of the lens;
- said lens including a second optical zone having at least a major portion thereof in the inferior portion of the lens;
- the focal length of said second optical zone being shorter than that of said first optical zone.
Dependencies are inferred from the claim text.