| 摘要 |
PROBLEM TO BE SOLVED: To prevent measuring precision from being influenced by the error of a distance by simplifying and miniaturizing the constitution of an optical system. SOLUTION: A luminous flux from an illuminating light source 6 is projected on a subject eye E and reflected light from an anterior ocular segment forms an image at an imaging means 4 through a measuring optical system 2. Radiated luminous fluxes from ring light sources 1 are projected on a cornea C and the image 1' formed on the means 4 by the system 2 is displayed on a display monitor 9. A luminous flux from the light source 5 passes through the periphery of the system 2 and is transmitted through a wedge prism 7 to be refracted to form two images 5' at the means 4. An arithmetic means 10 detects the positions of these images 5', calculates the direction and quantity of the deviation of the system 2 and drives the system 2 automatically so as to match with the eye E. When positioning is performed to some degree, the light source 6 is turned off and the video of the means 4 is fetched to the means 10 in order to measure the shape of the cornea.
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