Studies are showing the world is slowly losing its vision. In recent years, nearsightedness, also known as myopia, has started to affect more and more people worldwide. Currently, more than 28% of the global population suffers from poor vision, a figure that is projected to increase to 50% by 2050 [1]. These values vary significantly between regions, but even the region with the lowest proportion of myopic individuals, Oceania, will see a substantial increase from 5% to 24% [1]. These alarming statistics need to be brought to the public’s attention and its causes need to be further explored.
Myopia most commonly comes with the lengthening of the eye from front to back, but the progression of vision loss is not fully understood. Studies show that genes, environment, and lifestyle may all be contributors. Newborns are usually slightly farsighted, and infants rarely experience nearsightedness [2]. However, once children enter school, they may begin to experience eye lengthening and myopia. Myopia is usually correlated with increased education, though the exact connection between the two is unclear. Some theories suggest that education increases the amount of near work, or work done a short distance from the eyes, resulting in vision loss [2]. Another related cause may be the lack of outdoor activity; studies on chickens revealed that exposure to bright light on a daily basis resulted in lower rates of myopia [2]. This research was extended to humans using light sensors, which confirmed the results. In addition to light intensity, the duration of light exposure also lowered myopia rates [2]. These results show that time outdoors plays an important role in decreasing the threat of myopic progression.
In addition, technological developments and global events in recent years may explain the continued rise in myopia rates. The most recent generations grew up spending considerable time with screens, increasing the amount of near work in the most developmental years of the eye. Indeed, time on the computer correlates with higher myopia in children [3]. However, screen time is not the only culprit — reading books poses a similar, if not greater risk. Furthermore, myopia risk is compounded by the fact that the near work activities that children engage in take away from time outdoors, which reduces the likelihood of myopia [3]. More recently, the restrictions of the COVID-19 pandemic further decreased the outdoor activities of children. Alongside decreased time outdoors, the use of computers also increased. Coupled with severely limited time outdoors, screening showed remarkable increases in myopic development in children when compared to the pre-pandemic years [4]. These jumps may accelerate increasing worldwide myopia rates. To combat growing myopia, public knowledge of how to prevent myopic development is necessary, along with new treatments to stop and reverse vision loss.
Treatment of myopia has evolved slowly over the years. The earliest form of myopia treatment came in the form of bifocals, glasses with a section for near work and another for viewing the distance. Though studies on bifocals have some flaws in their experimental design, evidence points to the success of bifocals [5]. Corrective contact lenses have also been used to slow myopia progression by flattening the eye in a method called orthokeratology, or OK. In this method, the user wears OK lenses at night that mold their eyes, eliminating the need for daytime glasses or contacts [5]. OK has been proven to be safe and effective, though some users complain about discomfort and the effectiveness decreases for individuals with more severe myopia [5]. Another option, surgery, offers a more permanent solution, but since 2007, the popularity of refractive surgery has declined steadily and substantially due to bad publicity [6]. Certain pharmaceuticals have also been proposed as solutions; specifically, atropine has been shown to be highly effective at slowing progression of myopia [5]. Many of these options can be used together, and personal preference often affects the chosen treatment, with many still preferring standard glasses or contacts [5]. These solutions provide a good foundation for future developments, which would mean less expensive, more efficient treatments.
The recent surge in myopia rates is perhaps best explained by the societal developments of the last few decades resulting in less time spent outdoors. The amount of near work has increased drastically, computers and other screens have allowed for more indoor activity, and the quarantining and virtual classes that became commonplace during the pandemic have complicated the issue further. Rates of myopia are rising considerably with every new generation, and to prevent catastrophic rates of vision loss, parents must know how to create the best environment for their children. There is a critical need for more effective treatments, which must be proposed, tested, and become widely used as soon as possible.
References
Holden, B. A., Fricke, T. R., Wilson, D. A., Jong, M., Naidoo, K. S., Sankaridurg, P., Wong, T. Y., Naduvilath, T. J., & Resnikoff, S. (2016). Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology, 123(5), 1036–1042. https://doi.org/10.1016/j.ophtha.2016.01.006
Chakraborty R., Read S.A., Vincent S.J. (2020) Understanding Myopia: Pathogenesis and Mechanisms. In: Ang M., Wong T. (eds) Updates on Myopia. Springer, Singapore. https://doi.org/10.1007/978-981-13-8491-2_4
Enthoven, C. A., Tideman, J. W. L., Polling, J. R., Yang-Huang, J., Raat, H., & Klaver, C. C. W. (2020). The impact of computer use on myopia development in childhood: The Generation R study. Preventive Medicine, 132, 105988. https://doi.org/10.1016/j.ypmed.2020.105988
Wang, J., Li, Y., Musch, D. C., Wei, N., Qi, X., Ding, G., Li, X., Li, J., Song, L., Zhang, Y., Ning, Y., Zeng, X., Hua, N., Li, S., & Qian, X. (2021). Progression of Myopia in School-Aged Children After COVID-19 Home Confinement. JAMA Ophthalmology, 139(3), 293–300. https://doi.org/10.1001/jamaophthalmol.2020.6239
Cooper, J., & Tkatchenko, A. V. (2018). A Review of Current Concepts of the Etiology and Treatment of Myopia. Eye & contact lens, 44(4), 231–247. https://doi.org/10.1097/ICL.0000000000000499
Corcoran, Kevin J. Macroeconomic landscape of refractive surgery in the United States, Current Opinion in Ophthalmology: July 2015 - Volume 26 - Issue 4 - p 249-254. https://doi.org/10.1097/ICU.0000000000000159