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Double masked study of progressive addition lenses
Journal of the American Optometric Association
|October 1, 1980
Summary
This study found that practitioner bias, not patient preference, significantly influences the acceptance of progressive addition lenses (PALs). Patient choice in bifocal selection suggests practitioner influence is key for variable focus lens adoption.
Area of Science:
- Ophthalmology
- Optometry
- Vision Science
Background:
- Progressive addition lenses (PALs) offer variable focus for presbyopia correction.
- Understanding patient and practitioner factors influencing PALs adoption is crucial.
Purpose of the Study:
- To compare the acceptance of two types of PALs: Varilux II and Ultravue.
- To investigate patient choices and practitioner bias in PALs prescription.
Main Methods:
- A double-masked study involving 54 patients with varying bifocal additions.
- Measurement of near field width before and after one-month trial periods for each lens type.
- Patients could freely select or substitute bifocals without cost.
Main Results:
- Patient selection data and influencing variables were recorded.
- The study observed that practitioners' biases may play a larger role than patient readiness in PALs acceptance.
- Near field width measurements provided objective data on lens performance.
Conclusions:
- Practitioner bias appears to be a more significant determinant of progressive addition lens acceptance than patient preference.
- Future research should explore strategies to mitigate practitioner bias for wider patient adoption of PALs.
- The study highlights the complex interplay between lens design, patient needs, and clinical practice in vision correction.