AUTHOR=Costa Marcelo Fernandes , Rego Livia Soledade , Henriques Leonardo Dutra , Martins Gaddi Carlo , Souza Givago Silva TITLE=Reduced eye optical quality contributes to worse chromatic thresholds in aging JOURNAL=Frontiers in Integrative Neuroscience VOLUME=17 YEAR=2023 URL=https://www.frontiersin.org/journals/integrative-neuroscience/articles/10.3389/fnint.2023.1129315 DOI=10.3389/fnint.2023.1129315 ISSN=1662-5145 ABSTRACT=Purpose

Aging causes substantial changes in the intraocular lens, which leads to a reduction in chromatic perception. We aimed to measure the ocular light dispersion component in relation to the reduction in color vision by aging.

Methods

Intraocular straylight was quantified psychophysically by C-Quant for light dispersion [Log(s)], reliability of the results (ESD), and psychometric sampling quality (Q). The Cambridge Color Test Trivector protocol measured the chromaticity thresholds for protan, deutan, and tritan color confusion axis in CIE 1976 u’ v’ units. We tested 224 subjects aged 24–68 years (106 men) with normal best-corrected visual acuity and without clinical evidence of cataracts.

Results

A significant positive correlation was found between ocular dispersion of light and chromaticity thresholds for protan (r = 0.42; p < 0.001), deutan (r = 0.49; p < 0.001) and tritan (r = 0.51; p < 0.0001) color confusion axes with a moderate effect size (η2 = 0.39). However, a weak contribution of the logarithm of the straylight in predicting the chromaticity threshold for protan (b = 0.15; p = 0.025), deutan (b = 0.27; p = 0.001) and tritan (b = 0.21; p = 0.001) color confusion axes was verified in the regression coefficients. The other two measurement quality parameters estimated in the C-Quant were not correlated with chromaticity thresholds, suggesting that there are no problems with the quality of the measurement performed.

Conclusion

An increase in ocular light dispersion that occurs physiologically with aging negatively impacts the chromaticity threshold in a similar manner across all three color confusion axes. The weak regression effects suggest that neural rather than optical processes were more related to the reduction in chromaticity in aging.