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

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.