An optically realistic model eye is described. The optically realistic eye model has an optical axis and includes: an anterior replaceable module comprising a model cornea, model iris and model lens rotatably mounted for rotation about said axis, said module being representative of an emmetropic or pathological natural eye； an enclosure located posterior to said module and adapted to enclose a retinal area within which an image of an external object is brought to focus by said module； and a photoactive device movable within said enclosure and retinal area and adapted to detect or reflect a portion of the image for inspection, processing or analysis.
