Abstract
Purpose :
Both yellow tint and a near addition have been proposed to reduce visual fatigue associated with extensive near work, in particular on digital devices. However, there is limited evidence on whether a combination of a yellow tint and near addition can have a synergic effect. In this study, we aimed to evaluate the combined effect of near addition and a yellow tint on visual fatigue measured objectively and subjectively.
Methods :
Forty-six young adults (mean age 28.7±6.9 SD) with normal vision were recruited. We used our recently-developed experimental setup (Spiegel DP, ARVO Abstract 5966, 2018) that quantifies visual fatigue as a slope of a linear fit through accommodative microfluctuations (AMFs) over time. The participants wore their habitual correction (“Habitual”) or yellow-tinted (a*=-5.05±0.37; b*=19.4±0.96; hue=103±2.85) single vision spectacles with their habitual correction and +0.6 D addition (“Yellow Add”). In a subset of subjects (21 out of 46), we additionally measured the AMFs through their habitual correction with yellow tint only (“Yellow Only”) or with their habitual correction with a +0.6 D only (“Add Only”). In addition, we collected a questionnaire evaluating subjectively their visual fatigue.
Results :
In agreement with our previous data, our experimental setup increased AMFs over 20 minutes (mean slope=0.001±0.0003 SD). Wearing Yellow Add lenses significantly reduced this trend (mean slope=0.00017±0.0004 SD; t45=2.16, p=0.037). In addition, AMF slopes with Habitual lenses were negatively correlated with the decrease of AMFs slopes with the Yellow Add lenses (r=-0.41, p=0.005). Wearing Add Only and Yellow Only lenses in a subset of subjects resulted in more variable data and the difference from Habitual lenses did not reach statistical significance (p>0.05). Subjective symptoms of visual fatigue increased by approximately threefold post-task; however, there was no difference between the conditions (p>0.05).
Conclusions :
We have demonstrated a benefit of combining near addition and a yellow tint in terms of reduction visual fatigue induced by extensive near work. Our data suggest that participants who were more prone to visual fatigue may benefit more from the Yellow Add lenses. On the other hand, this beneficial effect was not reliably captured by subjective evaluation, suggesting that methods using objective markers of visual fatigue may be more sensitive in a short time frame.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.