Stand magnifiers: an evaluation of new optical aids from COIL.

This paper discusses stand magnifiers and the optical parameters that clinicians should know in order to understand the viewing requirements and the expected resolution for low vision patients. We report on measurements made of key optical parameters of a new series of stand magnifiers from Combined Optical Industries Limited (COIL) and comparison is made to the previous series of stand magnifiers from the same manufacturer. These results illustrate that manufacturers' specifications of optical parameters are generally inaccurate and misleading. We urge manufacturers to provide clinically relevant information about their optical products.