Effect of reading with a mobile phone and text on accommodation in young adults

Abstract

Purpose To investigate the effects of reading with mobile phone versus text on accommodation accuracy and near work-induced transient myopia (NITM) and its subsequent decay during near reading in young adults with mild to moderate myopia. Methods The refractions of 31 young adults were measured with an open-field autorefractor (WAM-5500, Grand Seiko) for two reading tasks with a mobile phone and text at 33 cm. The mean age of the young adults was 24.35 ± 1.80 years. The baseline refractive aspects were determined clinically with full distance refractive correction in place. The initial NITM and its decay time and accommodative lag were assessed objectively immediately after binocularly viewing a mobile phone or text for 40 min. Results The mean ± standard deviation (SD) initial NITM magnitude was greater for reading with text (0.23 ± 0.26 D) than for reading with mobile phone (0.12 ± 0.17 D), but there was no significant difference between the two reading tasks (p = 0.082). The decay time (median, first quartile, and third quartile) was 60 s (16, 154) and 70 s (32, 180) in the phone task and text task groups, respectively. There was also no significant difference in the decay time between the two reading types in general (p = 0.294). The accommodative lags of text tasks and mobile phones tasks were equivalent (1.27 ± 0.52 D vs 1.31 ± 0.64 D, p = 0.792). Conclusion There were no significant differences in accommodative lags and the initial NITM and its decay time between reading with a mobile phone and text in young adults.

Greater axial elongation associated with low accommodative lag: new insights on accommodative lag theory for myopia

“…The findings of Hue et al 19 (target at 33 cm) and Park et al 15 (target at 40 cm) indicated that watching a video on a digital screen (iPod, smartphone) caused a greater lag of accommodation when compared to reading text on paper. Furthermore, the results from the current study showed a significant difference in the lag of accommodation between reading text on paper and on a smartphone (the lag being greater with the smartphone), while more recent findings by Liang et al 27 found no significant difference in the lag of accommodation (at 33 cm) when reading text on a smartphone or paper. However, in the study of Liang et al, 27 different targets were used for the visual tasks and the measurement of accommodation.…”

“…Furthermore, the results from the current study showed a significant difference in the lag of accommodation between reading text on paper and on a smartphone (the lag being greater with the smartphone), while more recent findings by Liang et al 27 found no significant difference in the lag of accommodation (at 33 cm) when reading text on a smartphone or paper. However, in the study of Liang et al, 27 different targets were used for the visual tasks and the measurement of accommodation. In the present investigation, we used the same targets for both the visual tasks and the accommodative response measurement.…”

Study of Lag of Accommodation After Using a Smartphone

“…Another study by Kim et al [32] showed an increase in the lag of accommodation after using a smartphone dependent on the vergence function of the subject's eyes. Liang et al [23] assessed the lag of accommodation after a 40-minute use of a smartphone and reading a printed paper and showed no increase in the lag of accommodation after near work, which is consistent with the results of a study by Kang et al [12]. In their study, lag of accommodation was assessed after near activity with smartphone and tablet, and after using these devices no significant difference in the lag of accommodation was seen.…”

“…The test results did not show statically significant differences between different activities; however, the number of participants in that study was small. Another study showed no significant difference in the mean of lag of accommodation after two near work, reading a book, and using a smartphone, [23]. In this study, the lag of accommodation, after 40 minutes of near work at a distance of 33 cm with a smartphone and reading book was examined.…”

Reduction in Accommodative Response of Schoolchildren by a Double-Mirror System

“…Currently, computers, communication, and consumer electronics are popular, and the age of users is decreasing year by year. These electronic reading devices make viewing distances closer, which causes eye fatigue [20][21][22][23]. In order to reduce accommodation and slow the progress of myopia, this study proposes a new simple design of a double-mirror system (DMS) to extend viewing distance; while an object is still placed at a near distance, a virtual image is located further in front of the eye, resulting in accommodative relaxation.…”