PURPOSE: To measure the refractive index of a cornea simply without the extraction thereof out of a human eye by arranging a stage for forming a light cutting surface in the sample to be measured lighting the slit tip and a stage for measuring an apparent thickness therein or the like on the material.
CONSTITUTION: A slit lighting system 1 composed of a light source 6, a condenser lens 7 for collecting an emitted light therefrom, a slit opening 8 for limiting the light from the condenser lens 7 in a shape of slit, reflection mirrors 9 and 10 for changing the direction of emission thereof reflecting the light from the slit opening 8 and an image forming lens 11 for forming an image of the light from the slit opening 8 on a cornea C to be inspected. A measuring arithmetic circuit 5 measures the width of the cornea image I0 formed through a reflection with a relay lens 15 and a half mirror 13, namely, the apparent thickness of the cornea C. This enables the measurement of the refractive index of the cornea simply and quickly without the extraction of the cornea out of a human eye.
TAKAGI KAZUTOSHI
TORII YOSHITAKA
