Impact of tablet's correlated color temperature on ocular and visual function in myopic children: a pilot study

This study aimed to determine whether a tablet's correlated color temperature (CCT) setting affects ocular and visual function in myopic children.

A total of 24 myopic children participated in this study. They were asked to watch a 30-min video at a distance of 33 cm on tablets with low (2800 K) and high CCT (8500 K) settings, in a random order on two different days. Near work-induced transient myopia (NITM), binocular vision function, tear break-up time (TBUT), and asthenopia questionnaire responses were evaluated before and immediately after the 30-min video-watching task.

A significant interaction (CCT setting*examination time) (F = 6.01, p = 0.02) was observed for NITM, showing a trend toward an increase in the average initial NITM from pre- to post-video viewing when using the high-CCT tablet compared to the low-CCT tablet. No significant interaction was observed for the other visual function, TBUT, and asthenopia symptom scores (all p > 0.05), although the 30-min task using the tablet did result in a reduction in TBUT and an exacerbation of some asthenopia symptoms (p < 0.05).

The 30-min tablet usage task decreased tear film stability and exacerbated some asthenopia symptoms but did not significantly affect other visual functions, regardless of the screen's CCT setting. The use of a high-CCT (8500 K) tablet induced a slightly, but significantly, higher initial NITM compared to a low-CCT (2800 K) tablet; however, given the small magnitude of this difference, its clinical relevance still needs to be confirmed.