Comparison of the influence of light between circularly polarized and linearly polarized smartphones on dry eye symptoms and asthenopia

Abstract

This paper aims to investigate the efficacy of circularly polarized light smartphones in affecting dry eye symptoms and asthenopia through a comparison with linearly polarized smartphones. One hundred twenty participants were randomly divided into four groups. Dry eye and asthenopia symptoms were evaluated using the Ocular Surface Disease Index (OSDI), Computer Vision Syndrome Scale 17 (CVSS17), Convergence Insufficiency Symptom Survey (CISS), and visual analogue scale (VAS). Objective ocular examinations were assessed by confusion flicker frequency (CFF), tear meniscus height (TMH), noninvasive break‐up time (NIBUT), conjunctiva redness, fluorescein tear break‐up time (FTBUT), corneal fluorescein staining, and the Schirmer I test. Tests were performed before and after a reading task. Subjective evaluations including the OSDI, CVSS17, and CISS were all significantly increased after reading on a linearly polarized smartphone, whereas no change was observed in the circular polarization groups in both light and dark environments. A significantly enlarged VAS was shown in all of the four groups, but a significant increase in ΔVAS only appeared in the linear polarization groups. There were significant decreases in TMH, NIBUT, conjunctiva redness, FTBUT, and CFF after reading on a linearly polarized smartphone but the circularly polarized smartphone had lesser effects on these parameters. Our study indicated that reading on linearly polarized smartphones may cause dry eye disorder, asthenopia, and ocular discomforts, whereas circularly polarized smartphones appears to minimize these adverse effects on eye dryness and visual fatigue in light and dark environments.

Analysis of the Outcomes of the Screen-Time Reduction in Computer Vision Syndrome: A Cohort Comparative Study

“…Moreover, Mou et al 10 revealed that smartphone with circularly polarized light was much better than smartphone with linearly polarized light in terms of alleviating CVS eye strain, DED, and ocular discomfort as circularly polarized light has closer properties of natural light. 10 …”

“… 40 Linearly polarized smartphones are responsible for asthenopia and reduced confusion flicker frequency. 10 Smartphone has adverse effects on binocular vision by decreasing the binocular accommodative facility. 44 Electronic devices might be responsible for accommodative disorders and convergence insufficiency in pediatric users.…”

“…Computer vision syndrome (CVS) is a multifactorial syndrome that basically affects the eye, the musculoskeletal system, the circadian rhythms, the behavioral and sleep patterns, the social lifestyle, the occupational performances, and the public health. [1][2][3][4][5][6][7][8][9][10][11] The American Optometric Association defined CVS as a group of eye-related and vision-related problems that result from prolonged computer, tablet, laptop, e-reader and cell phone use. 1 The ocular complaints include dry eye disease (DED), visual blur, reduced visual performances, eye strain, asthenopia, accommodation-convergence imbalance, diplopia, and near objects visualization difficulties.…”

Proper rest during the long-time reading on smartphones may be a convenient and effective pevention strategy for DED and asthenopia

“…The research intended to recruit patients in order to have a signi cant clinical difference with a con dence interval of 95 % power (=0.05) based on a previous research sample size calculation n=30 [14] .…”

“…13 However, current treatments for DED have limited e cacy, for this reason, the best way to cope with the disease was taking preventative measures. Our previous studies focus on the effect of screen performance and found that circularly polarized screen and eINK screen can minimize subjective discomfort and ocular surface disorder when reading on smartphones 14,15 . The problem of penetration rate has to be taken into account, so we attempt to nd a simple, convenient and effective prevention strategy.…”