

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original...

A practical guide to the use and maintenance of the phoroptor, a diagnostic instrument used in ophthalmology. De Zeng's work includes detailed explanations and illustrations of the various parts of the instrument and the techniques used for refraction. This work has...
