Apparatus for corneal surgery

An apparatus for corneal surgery to correct a refractive error by ablating corneal tissue with a laser beam emitted from a laser source and delivered onto a cornea of a patient's eye with a light delivering optical system, the apparatus comprising an irradiation area limiting device for limiting an irradiation area of the laser beam and for varying the irradiation area, a first control device for controlling the irradiation area limiting device so as to reduce an ablation amount as the laser beam irradiates further away from a flattest meridian of astigmatism whereby effecting astigmatic correction, a second control device for controlling the irradiation area limiting device so as to increase an ablation amount as the laser beam irradiates further away from a steepest meridian of astigmatism whereby effecting astigmatic correction, and an arithmetic device for dividing a refractive power required for astigmatic correction into halves approximately equally so that an approximately half of the astigmatic correction is achieved by the first control device and the residual astigmatic correction is achieved by the second control device.