DeZeng Retinoscope Catalog PDF file. This is a four page flyer describing four models of DeZeng retinoscopes. The DeZeng Electric Retinoscope was used to determine the refractive state of the eye. The adaptation to electricity in the early 1900’s made ophthalmic instruments vastly more useful. Previously oil lamps and candles had been used to provide illumination from reflecting mirrors.
The DeZeng company eventually became American Optical and most recently Reichert company.