Abstract
Purpose :
There have been several reports showing visual disturbance such as declines in contrast sensitivity after wearing cosmetically tinted contact lenses. However, little is known about the mechanism. Some studies showed the relationship between loss of visual function and increases in higher-order wavefront aberrations (HOAs) in tinted contact lens wearers, but the influence of light scattering on visual function has not been examined in detail. Our hypothesis is that tinted contact lenses increase forward light scattering (FLS), thereby reducing visual function. In this study, we investigated the influence of cosmetically tinted soft contact lenses on visual function and FLS as well as HOAs.
Methods :
Twenty-seven eyes of 27 healthy volunteers were examined. The subjects’ age was 33.9 ± 9.6 (mean ± SD) years. Visual acuity, contrast sensitivity, FLS, and HOAs were measured after wearing the tinted contact lens (Freshlook® Dailies®, Alcon). The same examinations were repeated after wearing a normal clear contact lens without tinted designs (Dailies® Aqua, Alcon).
Contrast sensitivity was evaluated with the Optec 6500 vision tester (Stereo Optical), and area under the log contrast sensitivity (AULSCF) was calculated. FLS was measured with the C-Quant 80000 (Oculus), and log straylight parameter (log(s)) was evaluated. HOAs were assessed with the KR-1W (Topcon), and the RMS of coma-like, spherical-like, and total HOAs was calculated for a 4-mm pupil. The obtained data were compared between the two lenses.
Results :
AULCSF after wearing the tinted lens was significantly lower than that after wearing the clear lens in both photopic and mesopic conditions (p < 0.05).
FLS after wearing the clear and tinted contact lenses was 0.98 ± 0.18 and 0.98 ± 0.17 log(s), showing no significant difference.
Coma-like and total HOAs after wearing the tinted lens were significantly larger than those after wearing the clear lens (p < 0.05), but spherical-like aberration was not. However, neither HOAs nor FLS were correlated with contrast sensitivity after wearing the tinted contact lens.
Conclusions :
The declines in contrast sensitivity after the wear of tinted contact lenses were confirmed, but the mechanism could not be explained by changes in HOAs and/or FLS in this study. Further studies are needed to elucidate the underlying mechanism especially regarding the role of light scattering.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.