Simulation of refraction and spherical aberration for lenses.
This simulation shows realistic refraction of parallel rays passing through a convex lens with spherical surfaces. Unlike the Convex and Concave Lenses simulation, where all the bending occurs at the center of the lens and all parallel rays pass exactly through the focus, this simulation uses Snell's law to determine the actual amount of bending at each of the surfaces of the lens. You can adjust the amount of curvature for each side of the lens, the index of refraction of both the lens and the material surrounding the lens, and the zoom level. The fact that the parrallel rays do not converge at a single point is due to spherical aberration.