Research studies of bifocals for myopia

Inadequacies of past clinical reports on bifocals for progressive myopia have fostered the use of scientific methods in gathering data, with control groups of patients in experimental research studies. A summary and discussion of these research studies suggest that myopic progression may be influenced by bifocals, including some effects which are clinically meaningful as well as statistically significant. Benefits are not universal among myopes but might be predictable on the basis of patient characteristics, diagnostic data, magnitude of the add, design of the segment, and environmental demands and conditions.