Image evaluation of ophthalmic devices.

Methods used in the ophthalmic industry to evaluate the optical image quality of correcting lenses have remained the same over many years. This is especially true for single-vision ophthalmic lenses. With the development of new optical designs and materials for correcting refractive errors and presbyopia, new procedures for evaluating lens performance are being explored. One such method is the measurement of the modulation transfer function. Over the last 2 years, we have been measuring modulation transfer functions on a variety of single-vision and bifocal contact lenses, progressive addition spectacle lenses, holographic-diffractive lenses, and intraocular lenses. In this article, the modulation transfer function procedure and its application and results from one study on safety goggles will be presented and discussed.