Photo-refractive keratectomy device for treatment of eye, directs centering and fixing light beams of different wavelengths onto eye

摘要

The keratectomy device uses a laser beam for ablating parts of the cornea. A fixing light beam (24) of a visible light wavelength is directed at the eye. A device determines the point (20) at which the fixing light beam enters the front surface of the cornea. A centering light beam (34) is directed coaxially with the fixing light beam onto the eye, and has a different wavelength. The position of the scattered light/Fresnel reflection of the centering light beam on the front of the eye is measured.