Ophthalmic apparatus

• US 7,320,518 B2
• Filed: 01/21/2005
• Issued: 01/22/2008
• Est. Priority Date: 01/27/2004
• Status: Active Grant

• Current Assignee: Nidek Company Limited
• Original Assignee: Nidek Company Limited
• Inventors: Miwa, Tetsuyuki
• Primary Examiner(s): Schwartz; Jordan
• Assistant Examiner(s): JONES, JAMES
• Application Number:
  US11/038,527
• Publication Number:
  US 20050162611A1
• Time in Patent Office: 1,096 Days
• Field of Search: 351/206
• US Class Current: 351/206
• CPC Class Codes: A61B 3/101 for examining the tear film
• CPC Class Codes: A61B 3/145 by video means

Abstract

An ophthalmic apparatus comprising: an illuminating optical system which projects light to an examinee'"'"' eye; an image pickup unit which color-photographs an interference image caused by interference of light reflected by a tear layer of the eye; and an analyzing part which dissolves the photographed interference image to a plurality of color components, determines an appearance of interference stripes of each color component based on a signal of each color component, and obtains a value indicating a dry eye symptom based on at least one of the number of interference stripes of each color component and changes in signal level of each color component.

Claims

1. An ophthalmic apparatus comprising:

an illuminating optical system which projects light to an examinee'"'"'s eye;

an image pickup unit which color-photographs an interference image caused by interference of light reflected by a tear layer of the eye; and

an analyzing part which dissolves the photographed interference image to a plurality of color components, determines an appearance of interference stripes of each color component based on changes in signal level of each color component on an analysis line within an analysis area of the interference image, and obtains a value indicating a dry eye symptom based on a sum or an average value of at least one of the number of the interference stripes of each color component and the changes in the signal level of each color component on the analysis line.

3. The ophthalmic apparatus according to claim 1, further comprising a blink detecting unit which detects that the eye has blinked,

wherein the image pickup unit photographs the interference image after a predetermined time from the blink.

4. The ophthalmic apparatus according to claim 1, further comprising a blink detecting unit which detects that the eye has blinked,

wherein the image pickup unit photographs the interference image at predetermined time intervals within a predetermined time from the blink.

2. An ophthalmic apparatus comprising:

an illuminating optical system which projects light to an examinee'"'"'s eye;

an image pickup unit which color-photographs an interference image caused by interference of light reflected by a tear layer of the eye; and

an analyzing part which dissolves the photographed interference image to a plurality of color components, determines an appearance of interference stripes of each color component based on a signal of each color component, and obtains a value indicating a dry eye symptom based on at least one of the number of the interference stripes of each color component and changes in signal level of each color component,

the analyzing part being arranged to differentiate weighting to each color component when obtaining the value indicating the dry eye symptom.

5. A ophthalmic apparatus comprising:

an illuminating optical system which projects light to an examinee'"'"'s eye;

an image pickup unit which color-photographs an interference image caused by interference of light reflected by a tear layer of the eye; and

an analyzing part which dissolves the photographed interference image to a plurality of color components, determines an appearance of interference stripes of each color component based on changes in signal level of each color component, and obtains a value indicating a dry eye symptom based on a sum or an average value of at least one of the number of the interference stripes of each color component and the changes in the signal level of each color component.