A good overview of the optical effectiveness of lens opacities can be obtained with retroillumination from the fundus, especially when creating a digital panorama from one image each with nasally and temporally decentered slit light. This technique—also with green light—is particularly suitable for intraocular lenses, whose texture, haptics, and shape can be well represented, as well as for a secondary cataract. The optically high-quality surfaces of intraocular lenses provide Purkinje images 3 and 4 of significantly better quality at the slit lamp than is known for a normal phakic eye. While the reflecting zones of intraocular lenses offer interesting variations of classical biomicroscopy, the size of the Purkinje images of the slit lamp’s filament mainly provides information about the radii of curvature of the refracting surfaces.