[An eye-model to show fundamental optical properties as related to refraction and glasses-testing (author's transl)]

A new model of the eye is presented, that can demonstrate quantitatively the principal optical concepts such as focal distance, refractive power, principal point, nodal point etc. Ametropias and their correction can be shown. This model can be used to illustrate the dependence of the vertex distance on the effective refractive power of a spectacle lens and the influence of a spectacle lens on the image size on the retina. The phenomena of retinoscopy can also be demonstrated very clearly. An instruction manual for the model exists that contains theory, control tests and suggested experiments.