Suggested New Methods for Photokeratoscopy a Comparison for Their Validities Part I

A fundamental relation between the nature of the corneal surface and the one of the keratoscope rings is found. On that basis three methods to measure the corneal topology are proposed. A comparison between these methods shows that for diffused light we should use a differential equation. On the other hand, to avoid the differentiation, the angle of orientation of the directed light should be known precisely. The precision of these methods vary from 0.02 mm to 0.1 mm according to the methods, the mathematical process and the corneal models which we use.