Abstract: A video Keratometer/Pachymeter comprising an array of illuminated points disposed in concentric circles around the optical axis of a television camera for definition of corneal surface contour by a method similar to the well know Placido, except that the isolated point ring format provides unambiguous back ray trace information to eliminate errors inherent in the prior art, in combination with a projected pattern of discrete points to elicit Tyndall images for definition of both anterior and posterior corneal surface by triangulation using multiple television cameras viewing the reflected and Tyndall images, substraction of a view of the eye with neither pattern superimposed as well as each pattern in sequence for isolation of the data containing points from the general clutter of background pictorial information.

Abstract: A Keratometer for ascertaining the shape of the corneal surface of the eye comprises a television camera with associated processing circuitry. The television camera receives a reflection of a target such as placido's disc from the surface of the cornea. The television image of the reflection of the placido disc from the corneal surface is subjected to digital analysis after treatment in an edge detector. The edge detector reduces the number of data points that must be processed to define the radius of each ring in the reflected placido disc image. The resultant data are processed to derive surface contour and to provide a display in tabular, graphic or pictorial form of the contour data so generated.