Optically induced hyperopic defocus: axial length changes in emmetropes from mobile screen exposure Original research study

Article Sidebar

PDF


Published: Aug 6, 2025
DOI: https://doi.org/10.24292/01.OT.240725
Keywords:
axial length, myopia, optical defocus, screen exposure

Main Article Content

Saif Ullah
Scholar Health sciences under specilization of Vision sciences and Optometry, Department of Applied Sciences, Lincoln University College, Malaysia
Muhammad Farooq Umer
Department of Preventive Dental Sciences, College of Dentistry, Faculty of Medicine, King Faisal University
https://orcid.org/0009-0007-3212-0188
Suriyakala P Chandran
Faculty of Medicines, Lincoln University College, Selangor Darul Ehsan, Malaysia
https://orcid.org/0000-0001-6904-7980

Abstract

Background: The rapid increase in smartphone screens led to eye problems. The study measured transient axial length variations during mobile screen exposure before and after hyperopic defocus.


Methods: A quasi-experimental study on students utilizing non-probability sampling was conducted at Al-Shifa Trust Eye Hospital. LogMAR measured visual acuity, and retinoscopy measured refractive status of right eye only. Samsung Galaxy A7 provided full-blue screen exposure. -3.00 DS lens in trial frame caused hyperopic defocus. IOL Master Zeiss 700 measured axial length and ocular biometrics. The online web program Data tab was entered, and data was analyzed.


Results: A total of 30 subjects, which includes 6 (20%) males and 24 (80%) females, with a mean age of 20.67 (±0.96) years. Mean visual acuity and Spherical Equivalent Refraction were 0.00 (±0.00) and 0.10 (±0.01). Comparing the median interquartile range (Median-IQR) pre-defocus axial length (PDAXL) and after defocus axial length (ADAXL), pre-defocus lens thickness (PDLT) and after defocus lens thickness (ADLT) following 1 h exposure to mobile screen a statistically significant difference were observed respectively – 23.2 (±0.93), 23.14 (±0.92), p value = 0.003 and 3.61 (±0.28), 3.61 (±0.22), p value = 0.001. Other ocular parameter like pre-defocus anterior chamber depth (PDACD) and after-defocus anterior chamber depth (ADACD), pre-defocus central corneal thickness (PDCCT) and after-defocus central corneal thickness (ADCCT) no statistically significant were observed respectively – 3.45 (±0.29), 3.44 (±0.26), p value = 0.861 and 528 (±31.50), 525.17 (±24.75), p value = 0.139.


Conclusion: Exposure to mobile screens in blue mode, along with hyperopic defocus, was found to cause axial length shortening, offering potential implications for managing myopia progression.

Downloads

Download data is not yet available.

Article Details

How to Cite
1.
Ullah S, Umer MF, Chandran SP. Optically induced hyperopic defocus: axial length changes in emmetropes from mobile screen exposure. Ophthatherapy [Internet]. 2025Aug.6 [cited 2026Feb.22];12(2):115-20. Available from: https://journalsmededu.pl/index.php/ophthatherapy/article/view/3160
Issue
Vol 12 No 2 (2025)
Section
Diagnostics
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Copyright: Medical Education sp. z o.o. License allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material, provided the original work is properly cited and states its license.

Address reprint requests to: Medical Education, Marcin Kuźma (marcin.kuzma@mededu.pl)

References

1. George DAS, George ASH, Shahul A. The Myopia Epidemic: A Growing Public Health Crisis Impacting Children Worldwide. Partn Univers Int Res J. 2023; 2(3): 120-38.
2. Morgan IG, Wu PC, Ostrin LA et al. IMI risk factors for myopia. Invest Ophthalmol Vis Sci. 2021; 62(5): 3.
3. Haarman AE, Enthoven CA, Tideman JWL et al. The complications of myopia: a review and meta-analysis. Invest Ophthalmol Vis Sci. 2020; 61(4): 49
4. Du R, Xie S, Igarashi-Yokoi T et al. Continued increase of axial length and its risk factors in adults with high myopia. JAMA Ophthalmol. 2021; 139(10): 1096-103.
5. von der Heide A. Fitting Soft Multifocal Customized Contact Lenses for Myopia Control: A Literature Review [PhD Thesis]. 2019.
6. Harb EN, Wildsoet CF. Origins of Refractive Errors: Environmental and Genetic Factors. Ann Rev Vis Sci. 2019; 5(1): 47-72.
7. Corke P. Light and Color. In: Robotic Vision. Springer Tracts in Advanced Robotics, vol 142. Springer, Cham 2022.
8. Lingham G. Investigating the Impact of Past Time Spent Outdoors in the Sun on Risk of Myopia in Young Adults. 2020. doi: 10.26182/8g8q-6y69.
9. Muralidharan AR, Lança CC, Biswas S et al. Light and myopia: from epidemiological studies to neurobiological mechanisms. Ther Adv Ophthalmol. 2022; 13: 25158414211059246.
10. Jiang X, Kurihara T, Torii H et al. Progress and Control of Myopia by Light Environments. Eye Contact Lens. 2018; 44(5): 273.
11. Koumbo M, Ornella I. An eye model involving short term exposure to optical defocus : central and peripheral eye length and choroidal thickness. 2020. doi: 10.26190/UNSWORKS/22733.
12. Pugazhendhi S, Ambati B, Hunter AA. Pathogenesis and Prevention of Worsening Axial Elongation in Pathological Myopia. Clin Ophthalmol. 2020; 14: 853-73.
13. Choi KY. Effect of optical defocus characteristics in the living environment and interaction with peripheral refractive error on myopia progression. 2021.
14. Schilling T. Effects of color-tinted lenses on visual behavior. Universität Tübingen; 2022.
15. Nickla DL, Wang X, Rucker F et al. Effects of Morning or Evening Narrow-band Blue Light on the Compensation to Lens-induced Hyperopic Defocus in Chicks. Optom Vis Sci. 2023; 100(1): 33-42.
16. Wang D, Chun RKM, Liu M et al. Optical defocus rapidly changes choroidal thickness in schoolchildren. PloS One. 2016; 11(8): e0161535.
17. Thakur S, Dhakal R, Verkicharla PK. Short-term exposure to blue light shows an inhibitory effect on axial elongation in human eyes independent of defocus. Invest Ophthalmol Vis Sci. 2021; 62(15): 22.
18. Jiang X, Pardue MT, Mori K et al. Violet light suppresses lens-induced myopia via neuropsin (OPN5) in mice. Proc Natl Acad Sci. 2021; 118(22): e2018840118.
19. Rucker FJ, Wallman J. Cone signals for spectacle-lens compensation: differential responses to short and long wavelengths. Vision Res. 2008; 48(19): 1980-91.
20. Jiang L, Zhang S, Schaeffel F et al. Interactions of chromatic and lens-induced defocus during visual control of eye growth in guinea pigs (Cavia porcellus). Vision Res. 2014; 94: 24-32.
21. Yu M, Liu W, Wang B et al. Short wavelength (blue) light is protective for lens-induced myopia in guinea pigs potentially through a retinoic acid-related mechanism. Invest Ophthalmol Vis Sci. 2021; 62(1): 21.
22. Hung LF, Arumugam B, She Z et al. Narrow-band, long-wavelength lighting promotes hyperopia and retards vision-induced myopia in infant rhesus monkeys. Exp Eye Res. 2018; 176: 147-60.
23. Lou L, Ostrin LA. Effects of narrowband light on choroidal thickness and the pupil. Invest Ophthalmol Vis Sci. 2020; 61(10): 40.
24. Strasburger H, Bach M, Heinrich SP. Blur Unblurred - A Mini Tutorial. I-Percept. 2018; 9(2): 204166951876585.
25. Lingham G, Mackey DA, Lucas R et al. How does spending time outdoors protect against myopia? A review. Br J Ophthalmol. 2019; 104(5): 593-9.
26. Myopia: animal models to clinical trials. Tan DTH, Beuerman RW, Seang-Mei S, Wong TY (eds.). World Scientific, Singapore 2010.
27. Czepita D, Gosławski W, Mojsa A. Refractive errors among students occupying rooms lighted with incandescent or fluorescent lamps. Ann Acad Med Stetin. 2004; 50(2): 51-4.
28. Kröger RH, Binder S. Use of paper selectively absorbing long wavelengths to reduce the impact of educational near work on human refractive development. Br J Ophthalmol. 2000; 84(8): 890-3.
29. Ofuji Y, Torii H, Yotsukura E et al. Axial length shortening in a myopic child with anisometropic amblyopia after wearing violet light-transmitting eyeglasses for 2 years. Am J Ophthalmol Case Rep. 2020; 20: 101002.