A Subjective Comparison Of Quality Of Vision Through Four Ophthalmic Materials.

Background: Many types of ophthalmic materials are available for use as corrective
spectacle lenses. Each material has certain qualities that can be seen as advantageous
when compared to other materials. A study of subjective ability to discriminate between
the optical qualities of different lens materials may aid in marketing, help distribute
higher quality materials to consumers, and convince professionals of the need to offer
these materials. Methods: Lenses made of CR-39, polycarbonate, 1.6 index plastic, and Trivex materials were distributed amongst four stations divided by lens powers and working distances. Undergraduate college students were asked to rank the lenses from best quality of vision to worst at each station. Participants were also asked opinion-based questions as to their preferred lens, willingness to pay extra for that lens, and the importance of having material options offered at the time of spectacle purchase. Results: Significant lens preferences were found primarily at stations of +/-2.50 D. There was
little consistency between stations and no difference found in rankings or preferences
when data grouped by sex and by the initial instructions received was compared. The
majority of participants did not agree that explanation of material differences is warranted
at the time of lens choice, but were willing to pay extra for their preferred lens.
Conclusions: Optical quality differences were not significantly observed at powers less
than or equal to +/-1.50 D. This knowledge will help gear the marketing and sale of
ophthalmic materials toward meeting each patient's specific needs without unnecessary
explanations or overwhelming numbers of options.