Ophthalmic talbot-moire wavefront sensor

• US 6,736,510 B1
• Filed: 02/04/2003
• Issued: 05/18/2004
• Est. Priority Date: 02/04/2003
• Status: Expired due to Term

• Current Assignee: Alcon Incorporated
• Original Assignee: Ware Tec Vision Systems Incorporated
• Inventors: Van Heugten, Anthony
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US10/357,980
• Time in Patent Office: 469 Days
• Field of Search: 351/205, 351/206, 351/211, 351/212, 351/221, 351/209, 351/210, 351/246, 351/204, 351/216, 351/213
• US Class Current: 351/221
• CPC Class Codes: A61B 3/1015 for wavefront analysis

Abstract

A system for measuring the eye comprising a light source 10 which sends a narrow collimated beam of light 12, to reflect from a beam splitter 14. The beam of light 12 enters the eye 16 through the pupil 17 where it is focused to a point 20 on the retina 18. The light 12 is reflected from the retina 18 where it passes through a series of relay lenses 22, 24. The light then passes through one or more reticles 26, 28. A CCD camera 30 records the shadow pattern formed by reticles 26, 28. The shadow pattern is digitized into a computer and algorithms are created to calculate the distortions. As a result of the above steps being performed, the refractive power of the eye can be measured at many points, simultaneously.

Claims

1. A system for measuring characteristics of the eye comprising:

(a) means for generating an optical wavefront, the diameter of the wavefront being less than the diameter of the pupil of the eye being measured;

(b) means to transmit the optical wavefront to the eye, the wavefront reflecting from a point on the retina of the eye;

(c) means to transmit the reflected wavefront from the eye to reticle means;

(d) one or more reticle means through which the reflected optical wave front is passed to create a shadow pattern;

(e) means for analyzing the shadow pattern to produce measurement data of the characteristics of the wavefront, thereby providing measurement characteristics of the eye.

2. The system of claim 1 wherein the optical wavefront is a collimated beam of light less than about 1 millimeter in diameter.

3. The system of claim 1 further comprising means for generating a collimated beam of a predetermined wavelength to generate the optical wavefront.

4. The system of claim 3 further comprising means to generate a collimated beam with a wavelength of from 770 to 790 nanometers.

5. The system of claim 4 further comprising means to generate a collimated beam with a wavelength of about 780 nanometers.

6. The system of claim 1 in which the means to transmit the reflected wavefront from the eye is a series of relay lenses.

7. The system of claim 6 in which the relay lenses are achromats.

8. The system of claim 1 in which the means to analyze the shadow pattern is a CCD camera which records the shadow patterns, which are digitized into a computer for analysis.

9. The system of claim 2 in which the collimated beam of light is less than 15 arc seconds of divergence or convergence.

10. The system of claim 7 comprising two relay lenses of equal focal length.

11. The system of claim 1 comprising a first reticle and a second reticle rotated with respect to the first reticle, creating a moiré

effect.

12. The system of claim 1 in which the measurement characteristics of the eye are transferred to an eye corrective device.

13. The system of claim 12 in which the corrective device is a laser surgery laser, eye cornea reshaping laser, or a corrective lens producing device.

14. The system of claim 12 in which the measurement characteristics of the eye are converted to Zernikes, prior to transfer to a corrective device.

29. The system of claim 1, 15 or 28 further comprising aperture means to narrow the diameter of the beam of light to less than the diameter of the pupil of the eye being measured.

30. The system of claim 1, 15 or 28 further comprising two systems used simultaneously, to measure both eyes simultaneously.

15. A system for measuring characteristics of the eye comprising:

(a) a light source for generating an optical wavefront, the diameter of the wavefront being less than the diameter of the pupil of the eye being measured;

(b) a beam splitter to transmit the optical wavefront to the eye, the wavefront reflecting from a point on the retina of the eye;

(c) relay lenses to transmit the reflected wavefront from the eye to one or more reticles through which the reflected optical wavefront is passed to create a shadow pattern;

(d) a camera to record the shadow pattern;

(e) digitizing the recorded shadow pattern into a computer;

(f) analyzing the digitized shadow pattern to produce measurement data of the characteristics of the wavefront, thereby providing measurement characteristics of the eye.

16. The system of claim 15 wherein the optical wavefront is a collimated beam of light less than about 1 millimeter in diameter.

17. The system of claim 15 further comprising means for generating a collimated beam of a predetermined wavelength to generate the optical wavefront.

18. The system of claim 17 further comprising means to generate a collimated beam with a wavelength of from 770 to 790 nanometers.

19. The system of claim 18 further comprising means to generate a collimated beam with a wavelength of about 780 nanometers.

20. The system of claim 15 in which the relay lenses are achromats.

21. The system of claim 16 in which the collimated beam of light is less than 15 arc seconds of divergence or convergence.

22. The system of claim 15 comprising two relay lenses of equal focal length.

23. The system of claim 15 comprising a first reticle and a second reticle rotated with respect to the first reticle, creating a moiré

effect.

24. The system of claim 15 in which the measurement characteristics of the eye are transferred to an eye corrective device.

25. The system of claim 24 in which the corrective device is a laser surgery laser, eye cornea reshaping laser, or a corrective lens producing device.

26. The system of claim 24 in which the measurement characteristics of the eye are converted to Zernikes, prior to transfer to a corrective device.

27. The system of claim 15 in which the camera is a CCD camera.

28. A system for measuring characteristics of the eye comprising:

(a) a light source for generating an optical wavefront comprising a collimated beam of light less than the diameter of the eye being measured, said collimated beam of light having a wavelength of about 780 nanometers;

(b) a beam splitter to transmit the optical wavefront to the eye, the wavefront reflecting from a point on the retina of the eye;

(c) two achromat relay lenses of equal focal length to transmit the reflected wavefront from the eye to a first reticle and a second reticle rotated with respect to the first reticle, creating a moiré

effect;

(d) a CCD camera to record the moiré

effect;

(g) digitizing the recorded moiré

effect into a computer;

(h) analyzing the digitized moiré

effect to produce measurement data of the characteristics of the wavefront, thereby providing measurement characteristics of the eye.