Ophthalmic apparatus

• US 5,231,430 A
• Filed: 07/30/1991
• Issued: 07/27/1993
• Est. Priority Date: 07/31/1990
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kohayakawa, Yoshimi
• Primary Examiner(s): Bovernick, Rodney B.
• Assistant Examiner(s): Dang, Hung Xuan
• Application Number:
  US07/738,145
• Time in Patent Office: 728 Days
• Field of Search: 351/200, 351/203, 351/211, 351/216, 351/222, 351/223, 351/237, 351/238, 351/239, 351/243
• US Class Current: 351/243
• CPC Class Codes: A61B 3/028 for testing visual acuity; for determination of refraction, e.g. phoropters

Abstract

An ophthalmic apparatus includes a lens having a diameter greater than the distance between the pupils of the eyes of a user to be tested, adapted to be disposed in front of the eyes, a first visual target, including a visual target portion and a surrounding field of view defining portion, disposed at or near a focal plane of the lens, and a light source for illuminating the visual target portion and the surrounding field of view defining portion.

Claims

1. An eye examination apparatus comprising:

a lens, having a diameter greater than the distance between the pupils of the eyes of a user to be tested, adapted to be disposed at a first position in front of the eyes;

a first wide visual target, comprising a visual target portion and a surrounding field of view defining portion, disposed at or near a focal plane of said lens; and

illumination means for illuminating said visual target portion and said surrounding field of view defining portion.

2. The eye examination apparatus recited in claim 1, wherein said lens has an optical power such that said visual target means appears to be 5-6 meters or more from the user.

3. The eye examination apparatus recited in claim 1, wherein said first visual target is fixed in the direction of the optical axis of said lens.

4. The eye examination apparatus recited in claim 1, wherein said lens has an optical axis and comprises lens portions spaced from the optical axis.

5. The eye examination apparatus recited in claim 1, wherein said surrounding field of view defining portion has a distant scene image thereon appearing to be approximately the same distance from the user as said visual target portion.

6. The ophthalmic apparatus recited in claim 1, wherein said illumination means comprises different light sources for illuminating said visual target portion and said surrounding field of view defining portion.

7. The eye examination apparatus recited in claim 1, wherein said lens comprises a plurality of lens elements, and wherein said apparatus further comprises:

means for retracting at least one of said plurality of lens elements away from the first position to a second position out of the optical path of an eye of the user while said first visual target is disposed at or near the focal plane of said at least one of said plurality of lens elements defined when said at least one of said plurality of lenses is in said first position, thereby permitting the performing of a near sight test of the eyes of the user.

8. The eye examination apparatus recited in claim 7, wherein said retracting means retracts another lens element, different from said at least one of said plurality of lens elements, away from the first position to a second position out of the optical path of an eye of the user while said first visual target is disposed at or near the focal plane of said another lens element defined when said another lens element is in said first position, thereby permitting the performing of another near sight test of the eyes of the user.

9. The eye examination apparatus recited in claim 7, wherein said first visual target is adapted to be removed from its position at or near a focal plane of said lens element when said lens element is disposed in front of the eyes of the user in the optical path thereof, wherein said apparatus further comprises a second wide visual target adapted to be disposed at or near a focal plane of said lens element to be used in the near sight test of the eyes of the user when said lens element is retracted to said second position by said retracting means, wherein said first and second visual targets have different kind of surrounding field.

10. An eye examination apparatus comprising:

a single lens, having a diameter greater than the distance between the pupils of the eyes of a user to be tested, adapted to be disposed at a first position in front of the eyes;

a first wide visual target, comprising a visual target portion and a surrounding field of view defining portion, disposed at or near a focal plane of said lens;

illumination means for illuminating said visual target portion and said surrounding field of view defining portion; and

means for retracting said lens away from the first position to a second position out of the optical path of an eye of the user while said first visual target is disposed at or near the focal plane of said lens defined when said lens is in said first position, thereby permitting the performing of a near sight test of the eyes of the user.

11. The ophthalmic apparatus recited in claim 10, wherein said first visual target is adapted to be removed from its position at or near a focal plane of said lens when said lens is disposed in front of the eyes of the user in the optical path thereof, wherein said apparatus further comprises a second wide visual target adapted to be disposed at or near a focal plane of said lens to be used in the near sight test of the eyes of the user when said lens is retracted to said second position, wherein said first and second visual targets have different kind of surrounding field.

12. An ophthalmic apparatus comprising:

two variable-diopter subjective ocular refractivity measuring lenses spaced apart and adapted to be disposed in front of the right and left eyes of a user to be tested;

a lens, having a diameter greater than the distance between the pupils of the eyes of the user to be tested, adapted to be disposed at a first position in front of the two variable-diopter subjective ocular refractivity measuring lenses;

a first wide visual target, comprising a visual target portion and a surrounding field of view defining portion, disposed at or near a focal plane of said lens; and

illumination means for illuminating said visual target portion and said surrounding field of view defining portion.

13. The ophthalmic apparatus recited in claim 12, wherein said lens has an optical power such that said visual target means appears to be 5-6 meters or more from the user.

14. The ophthalmic apparatus recited in claim 12, further comprising:

a light beam divider positioned between said two variable diopter subjective ocular refractivity measuring lenses and said lens; and

an objective ocular refractive power measuring system positioned to receive light from said light beam divider.

15. The ophthalmic apparatus recited in claim 14, wherein said objective ocular refractive power measuring system comprises display means for displaying images of the anterior portion of the user'"'"'s right and left eyes.

16. The ophthalmic apparatus recited in claim 15, further comprising left-and-right eye direction moving amount detecting means for detecting the distance between the pupils of the eyes of the user according to the images of the anterior portion of the right and left eyes of the user, and wherein said two variable diopter subjective ocular refractivity measuring lenses are displaceable in a direction connecting the right and left eyes of the user in order to adjust the distance between said two variable-diopter subjective ocular refractivity measuring lenses to be equal to the distance between the pupils of the right and left eyes of the user.

17. The ophthalmic apparatus recited in claim 12, wherein said first visual target is fixed in the direction of the optical axis of said lens.

18. The ophthalmic apparatus recited in claim 12, wherein said lens has an optical axis and comprises a lens portion spaced from the optical axis.

19. The ophthalmic apparatus recited in claim 12, wherein said surrounding field of view defining portion has a distant scene image thereon appearing to be approximately the same distance from the user as said visual target portion.

20. The ophthalmic apparatus recited in claim 12, wherein said illumination means comprises different light source for illuminating said visual target portion and said surrounding field of view defining portion.

21. The ophthalmic apparatus recited in claim 12, wherein said lens comprises a single lens, and wherein said apparatus further comprises:

means for retracting said lens away from the first position to a second position out of the optical path of an eye of the user while said first visual target is disposed at or near the focal plane of said lens defined when said lens is in said first position, thereby permitting the performing of a near sight test of the eyes of the user.

22. The ophthalmic apparatus recited in claim 21, wherein said first visual target is adapted to be removed from its position at or near a focal plane of said lens when said lens is disposed in front of the eyes of the use in the optical path thereof, wherein said apparatus further comprises a second wide visual target adapted to be disposed at or near a focal plane of said lens to be used in the near sight test of the eyes of the user when said lens is retracted to said second position by said retracting means, wherein said first and second visual targets have different kind of surrounding field.

23. The ophthalmic apparatus recited in claim 12, wherein said two dipoter-value-variable subjective ocular refractivity measuring lenses are displaceable in a direction perpendicular to the optical axis thereof in order to adjust the distance between said two variable-diopter subjective ocular refractivity measuring lenses to be equal to be equal to the distance between the pupils of the right and left eyes of the user.

24. The ophthalmic apparatus recited in claim 12, wherein said lens comprises a plurality of lens elements, and wherein said apparatus further comprises:

means for retracting at least one of said plurality of lens elements away from the first position to a second position out of the optical path of an eye of the user while said first visual target is disposed at or near the focal plane of said at least one of said plurality of lens elements defined when said at least one of said plurality of lens elements is in said first position, thereby permitting the performing of a near sight test of the eyes of the user.

25. The ophthalmic apparatus recited in claim 24, wherein said retracting means retracts another lens element, different from said at least one of said plurality of lens elements, away from the first position to a second position out of the optical path of an eye of the user while said first visual target is disposed at or near the focal plane of said another lens element defined when said another lens element is in said first position, thereby permitting the performing of another near sight test of the eyes of the user.

26. The ophthalmic apparatus recited in claim 24, wherein said first visual target is adapted to be removed from its position at or near a focal plane of said lens element when said lens element is disposed in front of the eyes of the user in the optical path thereof, wherein said apparatus further comprises a second wide visual target adapted to be disposed at or near a focal plane of said lens element to be used in the near sight test of the eyes of the user when said lens element is retracted to said second position by said retracting means, wherein said first and second visual targets have different kind of surrounding field.