Abstract
Purpose: To evaluate claims of contrast improvement by tinted night driving glasses (TNDG) during mesopic luminance conditions. Methods: Contrast sensitivity functions (CSF) were measured in two trained myopic subjects, aged 20 and 34 years, with no known eye disease and normal foveal fusion. Both were fully corrected and their accommodative abilities were 13D and 8D, respectively. CSF with and without glare, induced by a Fostec DCR(r) II Light with four fiberoptical branches, was measured with the Morphonome(r) 4.2.4 image psychophysics software at two spatial frequencies (3 and 23 cpd). All measurements were done with the subjects wearing prescribed glasses, TNDG (Zeiss Clarlet 1.5 GOLD ET 015), and ophthalmic test lenses, with TNDG and test lenses being of equal dioptric value. Results: TNDG were found to perform better than prescribed glasses, especially subjectively. CSF was improved both with and without the presence of glare sources. However, no difference was found between TNDG and test lenses, neither with nor without glare. Conclusion: CSF was not significantly improved by tinted night driving glasses. Subjectively, the TNDG were preferred by both test subjects. Our findings indicate that at the higher spatial frequency the major improvements are due to the correction of night myopia.