Background: The use of electronic reading devices has increased dramatically. However, some individuals report increased visual symptoms when reading from electronic screens.
Objective: This investigation compared reading from two electronic devices (Amazon Kindle or Apple Ipod) versus hardcopy text in two groups of 20 subjects.
Methods: Subjects performed a 20 min reading task for each condition. Both the accommodative response and reading rate were monitored during the trial. Immediately post-task, subjects completed a questionnaire concerning the ocular symptoms experienced during the task.
Results: In comparing the Kindle with hardcopy, no significant difference in the total symptom score was observed, although the mean score for the symptoms of tired eyes and eye discomfort was significantly higher with the Kindle. No significant differences in reading rate were found. When comparing the Ipod with hardcopy, no significant differences in symptom scores were found. The mean reading rate with the Ipod was significantly slower than for hardcopy while the mean lag of accommodation was significantly larger for the Ipod.
Conclusions: Given the significant increase in symptoms with the Kindle, and larger lag of accommodation and reduced reading rate with the Ipod, one may conclude that reading from electronic devices is not equivalent to hardcopy.
Keywords: Accommodation; Ipod; Kindle; computer vision syndrome.