Date of Award
Master of Science in Vision Science
John R. Roggenkamp
Seventeen presbyopic subjects with a need of an occupational lens for intermediate distance tasks were selected from the Pacific University faculty and staff for fitting with the Varilux progressive addition lens (PAL) and an experimental PAL manufactured by Essilor Corporation. Subjects wore each set of lenses for a period of three weeks and responded to a questionnaire assessing adaptability, visual comfort, visual acuity, and effectiveness at intermediate tasks. Subjects were then given both sets of lenses for one week. When finished they were asked to make a choice of which lenses they preferred for occupational and recreational tasks. The results indicate that the experimental lens is not significantly better than the Varilux for occupational or recreational use.
Messerschmidt, Forrest B. and White, Chris T., "A comparison of new occupational progressive lens versus the Varilux for occupational use" (1988). College of Optometry. 149.