Eye Disorders in Hindsight: The Rising Concerns of Myopia during COVID-19
By Vicky Nguyen, Lord Byng Secondary School, Vancouver, British Columbia, Canada
Frequent headaches while looking at digital screens. Squinting eyes to look at objects far away. Constant eye fatigue at work. These are all signs of myopia, or nearsightedness, one of the most common eye disorders in the world. According to the World Health Organization (WHO), the global rate of myopia increased from 22% to 33% from 2000 to 2020 (WHO, 2015). With the ubiquity of technology, especially during the COVID-19 pandemic, the world’s susceptibility for myopia is on the rise.
During the COVID-19 pandemic, the use of electrical devices has spiked due to communication, entertainment, and learning demands. A study of families in Canada reported an 87% rise in screen time for children during the pandemic (Carroll et al., 2020), while another in China found that 70% of its participants reported higher screen time (Hu et al, 2020). Furthermore, with social distancing and community lockdowns, many people avoid going outside except for essential purposes. These seemingly integral parts of our pandemic lifestyle are actually causal factors of myopia.
On an anatomical level, myopia is caused by a refractive error: an excessive curvature in the cornea, the protective outer layer of the eye (Seltman, 2020). This results in light entering the eye changing focus on the light-sensitive retina. Images focus in front of the retina, instead of precisely like in a non-myopic person, resulting in blurred visions in distant objects rather than nearby ones.
Myopia is classified into high myopia and degenerative myopia (Seltman, 2020). High myopia occurs when the eyeball develops past the normal threshold. Degenerative, or malignant myopia, is more rare and inheritable. It often affects teenagers and exacerbates in adults, giving rise to higher possibilities of retinal detachment and abnormal blood vessel development. However, in most cases, eyeglasses and contact lenses are effective in visual correction, as they aid the light in focusing at the right spot on the retina (American Optometric Association, n.d.). Other methods, such as laser surgery, directly reshape the cornea by removing a small amount of corneal tissues.
There are many factors leading to myopia, such as genetics and environmental conditions. While heredity accounts for 80% of refractive error cases, it is not solely responsible for the recent substantial growth in myopia (Tedja et al., 2019). In Singapore, where myopia rates reach around 83% in young adults (Lam, 2019), myopia is more prevalent in people of Chinese, Indian, and Malay descent in Singapore than Indians in India and Chinese in China (He et al., 2009). Given that the average screen time for children in Singapore is 35 hours per week, 3 hours more than the global average, the high rates of myopia there are understandable (DQ Institute, 2018). Therefore, while genes play a part in myopia risk, environmental influences should not be viewed lightly when assessing the causes of myopia.
The risks of myopia nearly doubled in teenagers who spend more than 6 hours daily in front of electronic devices (Hansen et al., 2019). Time spent outdoors is also intricately linked to the rise in numbers of people with myopia. Children who spend an additional of 40 minutes outdoors every day experienced a 9.1% lower myopia rate than those who did not in 3 years (He et al., 2015). Although there is no evident explanation for this relationship, a theory proposes that the time outdoors and light concentration control dopamine production in the retina, which affects eye growth (Tedja et al., 2018). Another possible explanation is that the higher light intensity outdoors contributes to slowing the development of myopia (Rose et al., 2018, as cited in Shi and Killeen, 2020), as the sun’s ultraviolet rays can regulate the cornea’s shape (Mayo Clinic, n.d.).
Myopia is proliferating in East Asia, Europe, and North America, where it is projected to increase in 24% by 2050. The estimated global productivity loss is US$ 202 billion due to vision errors including myopia (WHO, 2015). Myopia is a prominent cause of moderate and critical vision impairments, being the second largest cause of blindness (WHO, 2015). In addition to causing severe vision impairments and financial burdens, myopia significantly reduces the quality of life. A study of Singaporean adolescents showed that those with vision disorders reported plummeting scores of satisfaction in school and social interactions (WHO, 2015). Hence, myopia needs to be addressed promptly to improve the quality of life worldwide.
While there is no absolute prevention from myopia, various safeguards can be taken to hinder its development. It is essential to take care of our eyes by taking eye exams regularly and applying the 20-20-20 method: look 20 feet away from close-up work for 20 seconds, every 20 minutes (Mayo Clinic, n.d.). Additionally, more time spent outdoors can help alleviate myopia risks. For children, parents and caregivers should take part in monitoring screen time and educating them about the impacts of myopia. The simplest actions, such as taking a break from the phone for a backyard soccer game, are actually the game-changers in creating a brighter vision for the world.
American Optometric Association. (n.d.). Myopia (nearsightedness). https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/myopia?sso=y.
Carr, B. J., & Stell, W. K. (2017, November 7). The Science Behind Myopia. Webvision: The Organization of the Retina and Visual System [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK470669/.
Carroll, N., Sadowski, A., Laila, A., Hruska, V., Nixon, M., Ma, D. W. L., & Haines, J. (2020). The Impact of COVID-19 on Health Behavior, Stress, Financial and Food Security among Middle to High Income Canadian Families with Young Children. Nutrients, 12(8), 2352. https://doi.org/10.3390/nu12082352
DQ Institute. (2018). 2018 National DQ Impact Report. https://www.singtel.com/content/dam/singtel/sustainability/Sustainability_reports_PDF%27s/2018_DQ_Singapore_National_Report.pdf
Hansen, M. H., Laigaard, P. P., Olsen, E. M., Skovgaard, A. M., Larsen, M., Kessel, L., & Munch, I. C. (2019, September 9). Low physical activity and higher use of screen devices are associated with myopia at the age of 16‐17 years in the CCC2000 Eye Study. Wiley Online Library. https://onlinelibrary.wiley.com/doi/10.1111/aos.14242.
He, M., Xiang, F., & Zheng, Y. (2015, September 15). Development of Myopia Among Children in China. JAMA. https://doi:10.1001/jama.2015.10803
Hu, Z., Lin, X., Chiwanda Kaminga, A., & Xu, H. (2020). The impact of coronavirus disease (COVID-19) epidemic on lifestyle behaviors and their association with subjective wellbeing among the general population in the Mainland China: a cross-sectional study (Preprint). Journal of Medical Internet Research, 22(8). https://doi.org/10.2196/21176
Lam, P.M. (2016, August 19). Speech by Dr Lam Pin Min, Senior Minister of State for Health, at the Opening of The Singapore National Eye Centre’s Myopia Centre, 16 August 2019. Ministry of Health of Singapore. https://www.moh.gov.sg/news-highlights/details/speech-by-dr-lam-pin-min-senior-minister-of-state-for-health-at-the-opening-of-the-singapore-national-eye-centre-s-myopia-centre-16-august-2019
Lanca, C., & Saw, S. M. (2020, January 13). The association between digital screen time and myopia: A systematic review. Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists), 40(2), 216–229. https://doi.org/10.1111/opo.12657
Mayo Foundation for Medical Education and Research. (2020, April 2). Nearsightedness. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/nearsightedness/symptoms-causes/syc-20375556.
McCarthy, C. S., Megaw, P., Devadas, M., & Morgan, I. G. (2006, November 13). Dopaminergic agents affect the ability of brief periods of normal vision to prevent form-deprivation myopia. Experimental Eye Research. https://doi.org/10.1016/j.exer.2006.09.018
Papolu, A. (n.d.). [Comparison diagram between normal vision and myopia]. The Conversation. https://ihpi.umich.edu/news/commentary-increasing-screen-time-during-covid-19-could-be-harmful-kids-eyesight
Shih, S.F., & Killeen, O. (2021, May 21). Commentary: Increasing screen time during COVID-19 could be harmful to kids' eyesight. Institute for Healthcare Policy & Innovation. https://ihpi.umich.edu/news/commentary-increasing-screen-time-during-covid-19-could-be-harmful-kids-eyesight.
Tedja M.S., Haarman A.E.G., Meester-Smoor M.A., Verhoeven V.J.M., Klaver C.C.W., MacGregor S. (2020). The Genetics of Myopia. Ang M., Wong T, (Eds.). Updates on Myopia. Springer, Singapore. https://doi.org/10.1007/978-981-13-8491-2_5
Tedja, M.S., Wojciechowski, R., Hysi, P.G., et al. (2018, May 28). Genome-wide association meta-analysis highlights light-induced signaling as a driver for refractive error. Nature Genetics. https://doi.org/10.1038/s41588-018-0127-7
World Health Organization. The Impact of Myopia and High Myopia. (2015, March 18). Retrieved June 23, 2021, from https://www.who.int/blindness/causes/MyopiaReportforWeb.pdf
Article Thumbnail: "Eyeglasses" by Muffet is licensed with CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/