Purpose:
To compare the contrast sensitivity function of a conventional PAL to new digitally surfaced designs with wavefront optimization, for both on and off-axis distance viewing.
Methods:
Contrast sensitivity (CS) was tested at 4, 8, 12 and 20 cpd at a test distance of 3 meters utilizing the Cambridge Research Systems Ltd. ViSaGe with a SONY GDM-F20 CRTand the Metropsis time interval, two-alternative, forced choice QUEST protocol. The subjects were tested gazing through a 6 mm aperture at the following three points in the lenses: Central fitting point (C), 12.5 deg temporally to the distance fitting point (I) and 6 deg below the fitting point (T). 28 eyes of presbyopic subjects (mean age 55 yo) were tested. All eyes were myopic (-0.75D to -8.00D Mean=-3.54D) with astigmatism (-1.25 to -2.50 mean=-1.69). Two lens designs were tested. A conventional (Panamic) and a digitally surfaced design with wavefront optimization (Physio).
Results:
CS improvements up to 20% (C), 27% (I), 72% (T) and 22% overall were measured with the Physio vs. the Panamic.
Conclusions:
In-Vivo contrast sensitivity with PALsmay be improved with newer designs.
Keywords: contrast sensitivity • presbyopia • spectacle lens