Aligning, calibrating, and systems testing of automatic ir optometers are greatly facilitated by using a liquid filled analog of the human eye. Characteristics of the eye analog that render it useful as a test element are (1) corneal refractive power comparable with that of the human eye, (2) spectral transmission properties similar to those of the ocular media, (3) rotatable cornea for simulation of astigmatism of any axial orientation, (4) movable fundus (image screen) to simulate an adequate range of refractive errors, and (5) easily replaceable cornea to obtain different amounts of astigmatism.