Mousumi Patro, B.Optom M.Optom

Elite School of Optometry, Chennai, India


The surge in smartphone usage, exceeding 20 hours weekly, has raised concerns about ocular health. (2) Prolonged use, particularly for reading or writing, is associated with elevated Intraocular Pressure (IOP), impacting both healthy individuals and glaucoma patients. Smartphone reading causes a more than 200% rise in IOP compared to printed text in healthy individuals. (3) A similar 150% increase in IOP with smartphone reading was reported by Ha et al., in medically controlled normal tension glaucoma patients when compared to printed text. (4) Under low-light conditions, smartphone work of more than 20 minutes led to a significant and sustained increase in IOP, with a subsequent drop below pre-work levels after cessation, indicating the dynamic impact of smartphone use on intraocular pressure. (5)

Factors contributing to the increase in IOP during smartphone use –

  1. Accommodation and convergence: Sustained active accommodation and convergence, resulting from prolonged smartphone viewing on a small screen with reduced font size and closer viewing distances, can lead to elevated IOP. (6)
  2. Extraocular Muscle (EOM) contraction: Extensive ocular motions and EOM during text scrolling and reading, compounded by varied smartphone orientations at times lead to sustained convergence of eyes in the vertical and/or horizontal direction contributing to increased IOP. (4)
  3. Psychophysiological Stress: Continuous information processing and concentration during smartphone use stimulate sympathetic input, inducing psychophysiological stress, which is closely linked to an elevation in intraocular pressure through the rise in norepinephrine levels. (7)
  4. Dry Eye: Stimulation of corneal nerves due to dry eye can activate afferent impulses through the trigeminal nerve, influencing IOP. While Perkins noted increased IOP in the same eye of rabbits after trigeminal nerve stimulation, the precise mechanism remains unclear. The irritation of corneal nerve endings in dry eye conditions might contribute to elevation of IOP. (5)
  5. Neck Flexion Posture: The neck flexion, averaging 33–45˚ from the vertical during smartphone use, potentially plays a role in elevating IOP, as sustained flexion increases IOP compared to neutral postures. (8,9)
  6. Dim Lighting: Under low-light conditions, more pronounced IOP changes occur, possibly due to increased pupil diameter and thickened iris in darkness. Additionally, increased visual fatigue and decreased visual performance during screen work contribute to further IOP elevation. (10)

Preventive measures for smartphone-induced IOP increase –

  1. Take regular breaks and follow the 20-20-20 rule.
  2. Maintain adequate posture: Hold the device at eye level and at a suitable distance away from the face.
  3. Limit screen time (11)


With the increasing prevalence of smartphone-related ocular health concerns, it’s crucial to recognise the multifaceted factors contributing to elevated IOP. In healthy individuals, these minor IOP changes may not have a substantial impact, but for patients with glaucomatous damage, consistent IOP increases from smartphone use can lead to progression. Consequently, it becomes crucial to adopt lifestyle factors related to smartphone usage, particularly for individuals with glaucomatous damage, to address and minimise potential risks.



  1.  TOI Tech Desk / TIMESOFINDIA.COM /  Apr 28, 2024. 6 simple tips to protect your eyes while using smartphones – times of India. The Times of India.
  2. Antona, B., Barrio, A. R., Gascó, A., Pinar, A., González-Pérez, M., & Puell, M. C. (2018). Symptoms associated with reading from a smartphone in conditions of light and dark. Applied Ergonomics, 68, 12–17.
  3. Srivastava, R. M., Agrawal, S., Amrin, N., & Bharti, D. (2023). Intraocular pressure changes while reading smartphone digital text versus printed text in healthy individuals and those with glaucoma. Journal of Glaucoma.
  4. Ha, A., Kim, Y. K., Kim, J.-S., Jeoung, J. W., & Park, K. H. (2019). Changes in intraocular pressure during reading or writing on smartphones in patients with normal-tension glaucoma. British Journal of Ophthalmology, 104(5), 623–628.
  5. Ha, A., Kim, Y. K., Park, Y. J., Jeoung, J. W., & Park, K. H. (2018). Intraocular pressure change during reading or writing on smartphone. PLOS ONE, 13(10).
  6. Bababekova, Y., Rosenfield, M., Hue, J. E., & Huang, R. R. (2011). Font size and viewing distance of handheld smart phones. Optometry and Vision Science, 88(7), 795–797.
  7. Lanigan, L. P., Clark, C. V., & Hill, D. W. (1989). Intraocular pressure responses to systemic autonomic stimulation. Eye, 3(4), 477–483.
  8. Malihi, M., & Sit, A. J. (2012a). Effect of head and body position on intraocular pressure. Ophthalmology, 119(5), 987–991.
  9. Lee, S., Kang, H., & Shin, G. (2014). Head flexion angle while using a smartphone. Ergonomics, 58(2), 220–226.
  10. Wang, D., He, M., Wu, L., Kao, A., Pekmezci, M., Singh, K., & Lin, S. (2012). Dark-light change of iris parameters and related factors among American Caucasians, American Chinese, and Mainland Chinese. Current Eye Research, 37(7), 599–605.
  11. Menon, R(n.d.). Prolonged Smartphone Use can lead to Increased Eye Pressure. Retrieved January 30, 2024 from