Tear film change and ocular symptoms after reading printed book and electronic book: a crossover study

Abstract

© 2019, Japanese Ophthalmological Society. Purpose: To evaluate and compare tear film changes and ocular symptoms after reading an electronic book (e-book) and a printed book. Study design: Clinical and experimental. Methods: Crossover study was conducted in 30 healthy volunteers, some of whom read an e-book and others a printed book for 20 minutes and then switched the following week. Tear meniscus height (TMH), non-invasive break-up time (NIBUT), fluorescein break up time (FBUT), corneal and conjunctival staining score, and questionnaires about seven ocular symptoms were evaluated before and after reading by both reading methods. Results: After reading an e-book, FBUT and NIBUT were significantly decreased (p<0.001for both). Similar to printed book readers (p=0.006, p=0.04, respectively). TMH and corneal and conjunctival staining score showed no significant differences in either group. Comparing the two groups, the e-book group showed more decrease in TMH, FBUT, and NIBUT (p>0.05). Ocular symptoms were significantly increased in both groups. The e-book group showed more increase in all symptoms, but only tearing (p=0.03) and burning sensation (p=0.02) were significantly different. Conclusions: Reading an e-book affected tear film instability and significantly increased burning sensation and tearing to a larger extend than reading a printed book.