Extended depth of field optics for human vision

• US 20030225455A1
• Filed: 03/24/2003
• Published: 12/04/2003
• Est. Priority Date: 09/15/2000
• Status: Active Grant

• Current Assignee: Wade Thomas Jr. Cathey
• Original Assignee: Wade Thomas Jr. Cathey
• Inventors: Cathey, Wade Thomas Jr.
• Granted Patent: US 7,025,454 B2
• Time in Patent Office: Days
• US Class Current: 623/6.11
• CPC Class Codes: A61F 2/1624 having adjustable focus; power activated variable focus means, e.g. mechanically or electrically by the ciliary muscle or from the outside
• CPC Class Codes: A61F 2002/1699 Additional features not otherwise provided for
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: G02B 3/00 Simple or compound lenses
• CPC Class Codes: G02C 7/024 Methods of designing ophthalmic lenses
• CPC Class Codes: G02C 7/028 Special mathematical design techniques
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00
• CPC Class Codes: G02C 7/042 Simultaneous type

Abstract

The present invention provides extended depth of field to human eyes by modifying contact lenses, intraocular implants, and/or the surface of the eye itself. This may be accomplished by applying selected phase variations to these optical elements (e.g., by varying surface thickness of the cornea of the eye). The phase variations EDF-code the wavefront and cause the optical transfer function to remain essentially constant within a range of distances from the in-focus position. This provides a coded image on the retina. The human brain decodes this coded image, resulting in an in-focus image over an increased depth of field.

Claims

1. A system for extending depth of field of an eye, comprising an optical mask positioned between retina of the eye and an object, the optical mask configured for altering an optical transfer function of the eye wherein the optical transfer function is substantially insensitive to distance between the eye and the object.

2. The system of claim 1, the mask selected from a group comprising thickness variations implemented with cornea of the eye, a contact lens and an intraocular implant.

3. The system of claim 1, the mask comprising an element configured for implementing a substantially cubic phase function that phase encodes a wavefront of light.

4. The system of claim 3, the element comprising a circularly symmetric element.

5. A method for extending depth of field of an eye, comprising steps of:

altering an optical transfer function of the eye thereby providing an altered optical transfer function such that the altered optical transfer function is substantially insensitive to distance between an object and the eye; and

encoding phase of light from the object with the altered optical transfer function.

6. The method of claim 5, the step of altering comprising a step of varying a thickness of cornea of the eye to alter the optical transfer function of the eye.

7. The method of claim 5, the step of altering comprising a step of placing an optical mask at the eye to alter the optical transfer function of the eye.

8. The method of claim 7, the step of placing an optical mask comprising a step of placing a contact lens on a surface of the eye.

9. The method of claim 7, the step of placing an optical mask comprising a step of implanting an intraocular implant in the eye.

10. The method of claim 5, the step of encoding comprising a step of encoding the phase of light with a substantially cubic phase function.