Schematic Eye designed to help students acquire the skill of performing retinoscopy. The back of the training eye can be adjusted from +4 to –6 to simulate different refractive errors. Hypermetropia (farsightedness) is created with the eye set to plus values while Myopia (nearsightedness) will result with minus values. Range can be extended with trial lenses. Plus powers add Myopia, minus adds Hypermetropia, cylinder lens simulates Astigmatism. Front holds up to three trial lenses. Two versions are offered: Basic provides simple pink target.