RECTILINEAR PHOTOKERATOSCOPE

摘要

12 RECTILINEAR PHOTOKERATOSCOPE A rectilinear keratoscope for determining the curvature of the anterior corneal surface of an eye. The keratoscope includes a translucent sheet having a curved pattern in the shape of a grid of intersecting individual curved lines. The pattern forms a substantially rectilinear grid image when reflected from a curved surface having a known radius of curvature. Deviations from a spherical surface can be qualitatively and quantitatively determined from examining the nature of the reflected image pattern and by measuring the spatial frequency of grid lines lying between a reference point and an image point corresponding to a point on the surface of the cornea whose refractive power is to be measured.