Tear pump contact lens

• US 4,640,594 A
• Filed: 09/13/1984
• Issued: 02/03/1987
• Est. Priority Date: 01/07/1982
• Status: Expired due to Fees

• Current Assignee: Richard Berger
• Original Assignee: Richard Berger
• Inventors: Berger, Richard
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Sugarman, Scott J.
• Application Number:
  US06/649,983
• Time in Patent Office: 873 Days
• Field of Search: 351/160 H, 351/160 R, 351/161, 351/162
• US Class Current: 351/160.00R
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00

Abstract

This invention relates to improvements in ophthalmic lenses and in particular to a three zone lens having a central optical portion connected by and secured to an intermediate tear pump zone which is secured and connected to an outer zone for retaining the lens on the eye. The central zone may function as a correction of vision or as a protection for the cornea of the eye. This central zone acting in conjunction with the intermediate tear pump zone of a bellow shape combine to form a pumping mechanism that is activated by the normal blinking of the eyelid. This pumping action causes tear fluid to be expelled and replenished in the area located behind the central zone and above the cornea of the eye. The fluids ingress and egress from this area through the tear layer located between the outer zone of the lens and the surface of the eye.

Claims

1. A semi-rigid polymeric corneal contact lens made to float upon and adhere to the cornea comprising a transparent, non-contacting, non-distorting central optical lens zone adapted to conform with the cornea and float on tear fluid, said central optical zone having an optical center, and inner and outer surface with the inner surface adjacent the tear fluid, and an intermediate reticulated zone of the same material as the central zone and of substantially uniform thickness but with at least one concave and one convex surface in relation to the cornea which is in the shape of a bellows to provide limited axial movement of the central zonea whenever an eyelid blink transmits a force to the central zone which displaces the intermediate zone in an axial inward direction with the cornea of the eye, without actually touching the cornea, to effect out flow of tear fluid from a fluid chamber, between the cornea and the eye, and at the completion of the blink to restore the central zone to an initial equilibrium position thereby creating a pressure differential to draw fresh tear fluid back into the tear chamber.

4. The contact lens of claim 1 wherein the intermediate zone in relation to the cornea has a first convex surface adjacent to the central zone and the concave surface adjacent the first convex surface with a second convex surface adjacent said concave surface and said lens further having a second central angle of a minium of 4 degrees and a maximum angle of 6 degrees formed by two intersecting lines both lines of which intersect at a point equidistant from all points on the inner surface of the central zone with one line also intersecting the annular line that symmetrically bisects the convex surface adjacent the central zone and the other line also intersecting with the annular line that symmetrically bisects the concave surface adjacent the convex surface.

2. A semi-rigid polymeric corneal contact lens made to float upon and adhere to the cornea comprising a transparant, non-contacting, non-distorting central optical lens zone adapted to conform with the cornea and float on tear fluid, said central optical zone having an optical center, and inner and outer surface with the inner surface adjacent the tear fluid, and an intermediate reticulated zone of the same material as the central zone and of substantially uniform thickness but with at least one concave and one convex surface in relation to the cornea which is in the shape of a bellows to provide limited axial movement of the central zone whenever an eyelid blink transmits a force to the central zone which displaces the intermediate zone in an axial inward direction with the cornea of the eye, without actually touching the cornea, to effect out flow of tear fluid from a fluid chamber, between the cornea and the eye, and at the completion of the blink to restore the central zone to an initial equilibrium position thereby creating a pressure differential to draw fresh tear fluid back into the tear chamber, said lens further having a first central angle of a minium of 25 degrees and a maximum of 38 degrees with said angle being defined by an intersection of two lines, both lines intersecting at a point which is equidistant from all points on the inner surface of the central zone, the first line also passing through the optical center of the central zone and the second line also passing through a point located on an annular line symmetrically bisecting the convex surface adjacent the central zone.

3. The contact lens of claim 2 wherein the intermediate zone is a different material from the central zone and a rubberlike material in nature to supply the deforming and restoring actions needed to pump the tear fluid.