Contact lens design for large amplitude translation
View Patent ↗The present invention is directed to a contact lens design where the optics position relative to the pupil is controlled by the lens relationship to the lower lid.
1. A contact lens having a top, a bottom, a rotational axis, a front surface and a base surface, the front surface including a plurality of zones, comprising:
an optical zone having a lower edge, including:
a distance vision zone having a curvature range that provides distance vision correction and having a first area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a first position within the optical zone so that the user's pupil is substantially subtended by the distance vision zone when the user is gazing at a substantially horizontal point in primary gaze;
a near vision zone, extending radially outward from the distance vision zone, having a second curvature range that provides near vision correction and having a second area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a second position within the optical zone so that the user's pupil is substantially subtended by the near vision zone when the user is gazing at a near vision point below the substantially horizontal point in down-gaze; and
a ledge zone disposed below the optical zone, that includes an undercut portion extending outwardly from the base surface to the front surface to enable engagement with a lower eyelid of a user and thereby provide vertical translation support for the contact lens when being worn by the user.
2. The lens of claim 1 , further comprising a transition zone extending from the lower edge of the optical zone to the upper edge of the ledge zone that provides a smooth transition from the ledge zone to the optical zone.
3. The lens of claim 1 , further comprising a bevel zone, extending radially outward that tapers to a narrow end.
4. The contact lens of claim 1 , wherein the distance vision zone has a center that is offset from the rotational axis of the contact lens.
5. The contact lens of claim 1 , wherein the distance vision zone has an oval shape.
6. The contact lens of claim 1 , wherein said lens has a thickness profile that increases along the vertical meridian.
7. The lens of claim 6 , wherein said lens has a thickness profile that is symmetric about the vertical meridian.
8. The lens of claim 1 , wherein the height of said ledge is between about 300-um and about 1200-um along the inferior vertical meridian.
9. The lens of claim 1 , wherein the height of said ledge is about 700-um.
10. The lens of claim 1 , wherein the ledge has an angular range between about 25 degrees and about 70 degrees measured from the vertical.
11. The lens of claim 1 , wherein the angle of the ledge is about 50 degrees to the vertical.
12. The contact lens of claim 3 , wherein the distance vision zone has an oval shape.
13. The contact lens of claim 1 , wherein the near vision zone is substantially concentric with the rotational axis and extends radially outward from the distance vision zone.
14. The lens of claim 1 , wherein said lens is capable of large amplitude translation in the range of about 2 mm to about 5 mm.
15. The lens of claim 1 , wherein said lens is capable of large amplitude translation in the range of about 3 mm to about 5 mm.
16. The contact lens of claim 1 , wherein the contact lens is comprised of soft contact lens material.
17. The contact lens of claim 16 , wherein the soft contact lens material comprises a silicon hydro-gel.
18. The contact lens of claim 16 , wherein the soft contact lens material comprises HEMA.
19. A mold capable of creating a lens wherein said created contact lens has a top, a bottom, a rotational axis, a front surface and a base curve, the front surface including a plurality of zones, comprising:
an optical zone having a lower edge, including:
a distance vision zone having a curvature range that provides distance vision correction and having a first area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a first position within the optical zone so that the user's pupil is substantially subtended by the distance vision zone when the user is gazing at a substantially horizontal point in primary gaze;
a near vision zone, extending radially outward from the distance vision zone having a second curvature range that provides near vision correction and having a second area that is sufficient to overlay a substantial portion of a pupil of a user and disposed in a second position within the optical zone so that the user's pupil is substantially subtended by the near vision zone when the user is gazing at a near vision point below the substantially horizontal point in down-gaze; and
a ledge zone disposed below the optical zone, that includes an undercut portion extending outwardly from the base curve to the front surface to enable engagement with a lower eyelid of a user and thereby provide vertical translation support for the contact lens when being worn by the user.
20. A method of making a lens capable of large amplitude translation comprising the steps of:
cutting a first surface in lens material, wherein said first surface comprises a base curve, including an undercut, wherein said undercut is designed to be engaged by a lower eyelid;
supporting said undercut;
transferring said lens material; and
cutting a second surface, wherein said second surface comprises a front surface; wherein the undercut extends outwardly from the base curve to the front surface.
21. The method of claim 20 , wherein said supporting step further comprises adding blocking material behind the base curve and undercut.
22. The method of claim 20 , wherein said second cut removes material from the superior boundary of the lens to produce an oblong lens shape.
23. A method of making a lens mold capable of creating a lens with large amplitude translation comprising the steps of: cutting a first surface in lens mold material, wherein said first surface comprises a male mold, including an undercut; supporting said undercut; transferring said lens mold material; and cutting a second surface, wherein said second surface comprises a female mold; wherein the undercut extends outwardly from the first surface to the second surface.