Patent ID: 6679876
Filing Date: 2004-01-20
Classification: A61F

Abstract:
A corneal surgery apparatus for ablating a part of a cornea by irradiating a laser beam onto the cornea of a patient's eye comprising:an irradiation optical system for irradiating the laser beam emitted from a laser light source onto the cornea, the irradiation optical system including a first irradiation optical system and a second irradiation optical system both to be used selectively, wherein the first irradiation optical system irradiates a relatively large spot beam, and the second irradiation optical system irradiates a relatively small spot beam; a variable aperture, which is disposed in the first irradiation optical system, having a variable opening region and profiling a large cross-sectional area of the beam perpendicular to an optical axis of the irradiation into an intended area; and an image forming lens forming an image of the opening region of the variable aperture on the cornea; a small aperture, which is disposed in the second irradiation optical system, having a fixed opening region and profiling the large cross-sectional area of the beam into a small area; a non-spherical lens, which is disposed close to the small aperture, having a flat surface in a center part of the lens and a curved surface in a periphery part of the lens and correcting an intensity distribution of the laser beam, which is changed when the beam passes through the opening region of the small aperture, to a specified intensity distribution having a relatively large intensity in a center part of the beam and a relatively small intensity in a peripheral part of the beam; and moving means for moving the small aperture and the non-spherical lens inside and outside an optical path of the laser beam.