Device-dependent variations in accommodation response during printed and digital reading

Abstract

Background: The increasing reliance on digital devices for reading and academic activities has raised concerns about how different screen types influence the accommodative system during prolonged near work.
Aim: This study aimed to compare the accommodation response of young adults when reading printed text and digital text displayed on a smartphone, tablet and computer.
Setting: This study was conducted at Universiti Teknologi MARA among 32 young adults aged 20–25 years with normal visual function.
Methods: Reading passages were presented under four conditions, namely printed text, smartphone, tablet and computer, in randomised order. Accommodation response was measured using the monocular estimation method (MEM) dynamic retinoscopy.
Results: A lead of accommodation was observed in all conditions, with significant variation across devices (Friedman test: χ² [3] = 15.932, P = 0.001). Smartphone reading produced the greatest accommodative lead and differed significantly from printed text (P = 0.029), tablet (P = 0.005) and computer (P < 0.001). Reading with printed text, tablet and computer produced similar accommodation responses.
Conclusion: Smartphones reading induces a greater accommodative lead than printed text and larger digital displays, suggesting that smaller digital screens impose a disproportionately higher accommodative demand.
Contribution: Accommodation response during reading is influenced by both device type and screen size. These findings provide clinically relevant evidence to support ergonomic guidance on device choice, viewing distance and screen use habits aimed at reducing visual stress and digital eye strain among young adults.