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As virtual networks and digital devices increasingly dominate the lives of teenagers, the time they spend on outdoor activities has significantly decreased. This shift has led to longer periods of screen time, causing the eyeball to elongate and making distant objects appear blurry, ultimately resulting in myopia (nearsightedness).
A prediction indicates that the incidence of myopia could double in the coming decades. However, Dr. Nilan Pawar from Aravind Eye Hospital in India believes this estimate underplays the severity, suggesting the incidence rate could actually triple.
According to the Nature journal, increasing outdoor activities is the best measure to prevent myopia. Scientists are actively seeking other solutions, such as simulating outdoor environments indoors, developing drug interventions, and exploring light-based preventative measures. These efforts aim to curb the alarming rise in myopia cases.
Bringing the Outdoors Indoors
Researchers conducted a study in East Asia, revealing that an extra hour of outdoor recess daily significantly reduces myopia incidence. However, implementing this consistently is challenging, especially in societies that prioritize academic achievement or urban areas with limited access to safe, green spaces. As a result, many ophthalmologists are exploring indoor alternatives.
A 2015 study in Northeast China found that installing brighter ceiling lights and blackboard lights in classrooms greatly reduced the annual myopia incidence among students from 10% to 4%. Despite the high demands for infrastructure modifications, researchers are also considering simpler solutions, such as creating nature-themed classroom environments with custom wallpapers and sky-blue ceilings with images of flying birds and balloons. The results showed that children in these classrooms experienced less eyeball elongation compared to those in plain white classrooms.
The Potential of Light Therapy
Some researchers believe that light is a crucial factor in myopia development and are experimenting with different wavelengths to prevent and inhibit the condition.
In Australia, researchers conducted pilot studies using specialized light therapy glasses that emit blue-green light, initially marketed to alleviate jet lag and improve sleep quality, but also showing potential in combating myopia.
Meanwhile, Dopavision, a medical device company in Berlin, is testing a virtual reality device that delivers short-wave blue light to the retina. Experiments on rabbits demonstrated significant increases in dopamine levels in their eyes. The company is now conducting larger clinical trials in Europe.
Raphael Goretz, a bioengineer at the University of Alabama at Birmingham, suggests ultraviolet light might be key in myopia prevention and treatment. Similarly, Richard Lang and his colleagues at Cincinnati Children's Hospital are testing similar lighting systems.
Controversies Around Light Therapy
However, one light therapy method called repeated low-level red light therapy (RLRL) is controversial. This desktop device emits low-intensity red light to enhance blood flow in the eye. A year-long clinical study by the ophthalmology team at the Hong Kong Polytechnic University found that children receiving this treatment twice daily for three minutes, five days a week, had half the myopia incidence compared to untreated children. The treatment has also been endorsed by the ophthalmology team at Queen's University Belfast, who plan to implement it in classrooms.
Despite its potential, there are concerns. A 12-year-old girl reportedly suffered retinal damage after red light therapy. Lisa Ostrin, a visual scientist at the University of Houston, warns that this therapy might cause thermal damage to the eyes, raising safety concerns.
Kevin Frick, co-chair of the Myopia Consensus Study Committee at the U.S. National Academies of Sciences, Engineering, and Medicine, emphasizes that while myopia interventions and treatments are on the rise, outdoor activities remain an excellent preventive measure. No indoor simulation can fully replace the benefits of real outdoor environments.
Reference:
Yi X, Wen L, Gong Y, Zhe Y, Luo Z, Pan W, Li X, Flitcroft DI, Yang Z, Lan W. Outdoor Scene Classrooms to Arrest Myopia: Design and Baseline Characteristics. Optom Vis Sci. 2023 Aug 1;100(8):543-549. doi: 10.1097/OPX.0000000000002046. Epub 2023 Jul 27. PMID: 37499167.
Hua WJ, Jin JX, Wu XY, Yang JW, Jiang X, Gao GP, Tao FB. Elevated light levels in schools have a protective effect on myopia. Ophthalmic Physiol Opt. 2015 May;35(3):252-62. doi: 10.1111/opo.12207. PMID: 25913873.
Liu H, Yang Y, Guo J, Peng J, Zhao P. Retinal Damage After Repeated Low-level Red-Light Laser Exposure. JAMA Ophthalmol. 2023 Jul 1;141(7):693-695. doi: 10.1001/jamaophthalmol.2023.1548. PMID: 37227712.
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