Patent ID: 6159202
Filing Date: 2000-12-12
Classification: A61B,A61F

Abstract:
A corneal surgery apparatus for ablating a cornea of an area used for sight of a patient's eye, comprising:an observation optical system for observing an anterior portion of the eye;a laser beam irradiating optical system for irradiating a laser beam which causes the cornea ablation; anda mechanism for tracking between an irradiating position of said laser beam by said irradiating optical system and the eye, said mechanism for tracking comprising:illuminating means for illuminating a relatively large area including an iris of the eye;a photographing optical system, of which optical axis is at a fixed position relative to the observation optical system, having a two-dimensional photographing element for photographing a pupil and the iris of the eye illuminated by said illuminating means;light-and-shade detecting means for detecting pixels of said two-dimensional photographing element in plural divided areas, then obtaining light-and-shade information of every said divided area; anddetermining means for determining a moving direction of said irradiating position by comparison of a distribution condition among each divided area having a distribution of pixels of a predetermined low photo-volume level.