Comparing reading comfort: iPad vs. E-reader

Activities that require near vision occupy a significant portion of our daily lives. We read, watch videos, and perform work-related tasks using electronic devices. Prolonged use of these devices can lead to a condition known as computer vision syndrome (CVS), characterized by ocular and behavioral symptoms, including eye dryness, irritation, visual fatigue, reduced attention, and decreased performance. 

The development of CVS is linked to reduced blinking while reading from a computer screen. However, it remains unclear whether handheld electronic devices, such as tablets, e-readers, or mobile phones, could also affect blinking frequency and induce other forms of eye discomfort while reading. 

There are two main types of electronic devices used for reading: e-readers that simulate paper books and LCD screens found in devices like iPads. Reading on an LCD screen can strain the eyes more than reading a paper book or e-reader display. This may be attributed to the fact that LCD screens emit brighter light, which causes pupils to constrict and reduces the frequency of blinking.

Researchers from the University of Zaragoza, Spain, assessed visual discomfort while using iPads or e-readers. They had study participants read on these devices for 21 minutes each while tracking their eye movements with Tobii Pro Fusion eye trackers. The researchers examined eye tracking metrics such as pupil diameter, fixations, saccades, and blinks, which can provide insights into visual discomfort during reading. They also measured eye aberration and retinal thickness before and after the reading session to get further insight into eye health.  

The study’s findings showed subtle variations in fixation and saccade patterns while reading from the two devices, with a tendency toward longer fixations while reading from an iPad. Study participants blinked more frequently while reading from an e-reader, suggesting potential differences in promoting eye dryness between the two devices. However, these differences did not reach statistical significance. The researchers did not find variations in visual quality measured by aberrometry or changes in retinal thickness when reading from the two devices. 

The authors concluded that an eye tracker and aberrometer can objectively measure visual performance and ocular health when using electronic devices. Further studies are necessary to explore the long-term effects of using electronic devices, as this study assessed the impact on vision only after 21 minutes of reading. 

Cited publication

Orduna-Hospital E, Munarriz-Escribano M, Sanchez-Cano A. Visual Quality, Motility Behavior, and Retinal Changes Associated with Reading Tasks Performed on Electronic Devices. Life. 2023; 13(8):1777.