Comparison of Accommodative Response After Reading from Electronic Devices versus Hardcopy

To assess the change in accommodative response between electronic devices and hardcopy text after prolonged reading.

There were 30 participants (N = 30), with a mean age of 24.29 ± 5.21 years. The accommodative response (lag or lead of accommodation, amplitude of accommodation, and accommodative facility) was measured before and after reading for 60 minutes from a printed book, a smartphone, and a laptop, with a 24-hour break between tasks. Secondary outcomes included comparisons of accommodative responses between hardcopy text and smartphone, smartphone and laptop, and laptop and hardcopy text.

Accommodative lag was initially 0.50 ± 0.00 D, with significant increases observed after 60 minutes of reading from a smartphone (1.25 ± 0.50 D), a laptop (1.75 ± 0.50 D), and a hardcopy text (1.50 ± 0.25 D). A greater lag was noted with laptop use compared to smartphone reading (P < 0.01). Accommodative facility was significantly reduced when reading from a laptop compared to both a smartphone (P < 0.01) and a hardcopy (P < 0.01). The binocular mean amplitude of accommodation was -7.50 ± 1.25 D with the laptop and -8.00 ± 1.00 D with the hardcopy, with a P-value of 0.085, indicating no statistically significant difference.

Prolonged near work significantly affects accommodative function, with laptops inducing the greatest accommodative lag and reduction in facility. Hardcopy reading preserved accommodative facility better than digital devices, while amplitude of accommodation showed minimal change. These results suggest that sustained laptop use may lead to greater visual strain compared to smartphones or printed text.