Zeiss Punktal
The spectacle lens that was sharp over the whole surface of the glass, not only in the middle.
Before 1912 spectacle lenses were flat or slightly curved and gave a blurred image at the edges. Moritz von Rohr at Zeiss calculated a curvature that made the image sharp even when looking to the side.
The Punktal lenses became a model for modern spectacle lenses. They show how optical firms used mathematics to make better visual aids.
Materials: Optical glass, ground with a curved surface
Manufacture: Calculated by Moritz von Rohr and made by Carl Zeiss in Jena from 1912.
The curved form of the lens that lets the eye see sharply in all directions.
The Zeiss Punktal mark at the edge of the lens.
Thin metal frames that show the shape of the lens.