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...http://www.google.com/patents/US5339121?utm_source=gb-gplus-sharePatent US5339121 - Rectilinear photokeratoscope
