초록 ▼

A method and device for benign, non-surgical external shaping of corneal tissue to compensate, by refractive correction, for deviations from normal focussing. Corneal tissue is externally gently removed by erosion to a maximum 30% depth, within several seconds, by an imperceptibly felt, highly contr

A method and device for benign, non-surgical external shaping of corneal tissue to compensate, by refractive correction, for deviations from normal focussing. Corneal tissue is externally gently removed by erosion to a maximum 30% depth, within several seconds, by an imperceptibly felt, highly controlled and limited area, isotonic water jet, exerting a total force of at most several ounces. The jet is directed to erode corneal tissue to provide an increase in curvature to correct for far-sightedness i.e., to refocus a perceived image from beyond retina onto the surface of the retina. To correct for near-sightedness and to refocus a perceived image from in front of the retina onto the surface of the retina, the jet is directed to flatten out by eroding, a central portion of corneal tissue, to decrease curvature. The jet is either applied by a nozzle or array of nozzles. The jet is applied and directed, in a computer controlled, raster or similar type movement, until the desired diopter change is effected. Since there is no heating of the cornea, with concomitant wound healing induced deviations, correction can be effected within a deviation range from normal of 0.25 diopters, comparable to that of corrective lenses and contact lenses.

대표청구항 ▼

[ What is claimed is:] [1.] In the method for refractive correction for deviations of an eye imaging system comprised of a cornea with an exposed front surface; a pupil; a lens; and a retina; from focussing perceived images directly on the retina of the eye; said method comprising the step of removi

[ What is claimed is:] [1.] In the method for refractive correction for deviations of an eye imaging system comprised of a cornea with an exposed front surface; a pupil; a lens; and a retina; from focussing perceived images directly on the retina of the eye; said method comprising the step of removing selected external portions of tissue from the front surface of the cornea, in an area defined by a maximum dilation of the pupil of the eye, whereby curvature of the front surface of the cornea is changed to a sufficient extent, whereby light rays from any point in a perceived image, passing through the cornea and the lens, are substantially optimally focussed thereafter on the retina; THE IMPROVEMENT COMPRISING:mechanically removing said selected portions of tissue from the front surface of the cornea by controlled erosion effected by impingement on said portions of tissue of at least one water jet having an impact velocity on said tissue of at least 200 meters/second.