👁️ Eye Lens Accommodation: Near Point, Myopia, Hyperopia and Presbyopia with Spectacle Lenses

A cut-away eye on an optical bench: move a candle and watch the ciliary muscle thicken the lens to keep the image on the retina. Change age, eyeball length, pupil and spectacle power to see myopia, hyperopia and presbyopia, and check the model against exact ray tracing.