Device and method for measuring cornea curvature

Abstract

The present invention provides a device and a method for measuring cornea curvature by using microreciprocal degree ring lights and focused lights for automatically eliminating measurement error caused by position change of an eye to be measured. The device for measuring cornea curvature comprises a microreciprocal degree ring light source for emitting ring lights to the cornea of an eye to be measured, a focused light source for emitting two spot type focused lights to the cornea of the eye to be measured, an image optics system for detecting an microreciprocal degree ring light image and focused light images that are reflected from the cornea, and an operation and control unit for obtaining the diameter R of the microreciprocal degree ring light image at a measurement mode and distance F between spots of the focused light images at the measurement mode from the microreciprocal degree ring light image and the focused light images detected by the image optics system, for compensating the diametric error of the microreciprocal degree ring light image as a consequence of position change of the eye, and calculating the cornea curvature of the eye to be measured according to the compensated microreciprocal degree ring light image.

Description

[0001] This application claims priority from Korean Patent Application No. 10-2008-0117273 filed on November 25, 2008. The entire disclosure of this Korean patent application is incorporated herein by reference. technical field [0002] The present invention relates to a method and apparatus for measuring the curvature of the cornea, and more particularly to such a method and apparatus for measuring the curvature of the cornea in which the Measurement error caused by changes in eye position. Background technique [0003] Various ophthalmic instruments are used to diagnose eye conditions, such as refractometers for objectively measuring the refractive power of the eye, devices for measuring the shape / curvature of the cornea (often called an opthalmometer), and The contact method measures intraocular pressure with a tonometer and the like. In particular, the keratometry device, as an optoelectronic measurement system, is composed of optical components, electronic components ...

AI Technical Summary

Problems solved by technology

[0009] This makes conventional devices have the disadvantage that the total measurement time becomes longer, and if the position of the eye to be measured changes when the aperture 14 is inserted, erroneous corneal curvature values ​​may be obtained

Moreover, it is also difficult for eye measurers to perceive the position changes of the measured eyes during the measurement process.

Conventional devices also have a disadvantage: conventional devices require an aperture 14, a precision motor 10 to drive the aperture 14, and a control circuit to drive them

This makes the product cost increase and the mechanical structure more complicated

At the same time, this also increases the probability of measurement calculation errors and mechanical failures, which in turn are caused by changes in the telecentric area of ​​​​the measurement light caused by the deviation of the aperture during use or the performance of the aperture motor.

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