Clinical Assessment of a Customized Free-form Progressive Addition Lens Spectacle

In a double-masked crossover trial, 95 experienced wearers wore customized free-form PAL
spectacles (Test) and standard non-free-form PAL spectacles (Control) for one week each. All
subjects wore both Test and Control spectacles, and the pair to be worn first was randomly
assigned. At dispensing and after 1 week of wear, subjects were tested for distance and near
visual acuity (VA) under both high and low contrast; in addition, 30 degree off-axis VA was
measured using a novel apparatus, as was the horizontal extent of undistorted vision at
reading distance. Subjects also completed a set of questionnaires detailing their
satisfaction levels, adaptation times, and preferences for Test or Control spectacles for
different visual tasks.

Inclusion Criteria:

- Presbyope

- Experienced PAL spectacle wearer

- Correctable to at least 20/25 in both eyes

- Able and willing to use Test and Control spectacles for 1 week each as primary form
of presbyopia correction

- Able and willing to complete all laboratory measurements and questionnaire batteries

Exclusion Criteria:

- Purchasing free-form PAL spectacles from the UC Berkeley Eyewear Center

- Having eye conditions or diseases that could potentially cause a decrease in visual
acuity over the course of participation in the study

- Having eye conditions or diseases that could potentially interfere with ability to
use Test and Control spectacles as primary form of presbyopia correction