Die Therapie des Auges mittels des farbigen Lichtes : Lehrbuch
A German medical textbook on treating eye disease with colored light, written by the Berlin ophthalmologist Ludwig Böhm and published by A. Hirschwald in 1862 for practising physicians and students. The plates mix hatched rotation discs labelled blau and roth, a numbered chart of tinted spectacle lenses in graded green washes, and a prism refracting rays across a solid black ground — useful for optical diagrams, colour-test charts, and hand-hatched geometric figures.
