New research suggests that the sharp rise in myopia rates around the world may be linked not only to screens, but rather to a more subtle factor: prolonged focusing at close distances under poor indoor lighting.
Researchers from the State University of New York College of Optometry report that the critical factor may be the amount of light that reaches the retina during prolonged near work, especially in indoor environments. When we focus on a phone, book, or tablet in dim light, the pupil constricts not because of the intensity of the light but rather to improve the clarity of the image. This constriction may reduce the amount of light reaching the retina, which may impair the visual stimulation necessary for normal eye development.
Myopia now affects about half of young people in the United States and Europe, and as high as 90% in some areas of East Asia. Although there are genetic factors, the rapid increase over a few generations strongly indicates the role of environmental factors.
The study proposes a new hypothesis linking multiple factors that seemed to be far apart, such as near work and dim lighting, and treatments such as atropine drops, multifocal lenses, and even spending time outdoors, to the development of myopia. According to this hypothesis, the common denominator between them all may be their effect on the amount of light that reaches the retina and the regulation of pupil constriction during the process of visual adaptation.
The results showed that negative lenses increase pupil constriction by enhancing the adaptation process when focusing at close distances, and this effect increases with reducing the viewing distance or using stronger lenses than necessary, especially when focusing for long periods. The researchers also noted that this effect is more severe in people who have already become nearsighted.
In contrast, exposure to bright light outside provides stronger stimulation of the retina, even as the pupil constricts to protect the eye from the brightness, which may help maintain healthy visual development.
If this hypothesis is confirmed, it may reshape prevention and treatment strategies, as it becomes important to maintain adequate lighting during close work, reduce the need for excessive adaptation by using appropriate visual aids, in addition to encouraging spending more time outdoors.
Although these results do not represent a final answer, they provide a testable physiological explanation that combines our daily visual habits, lighting conditions, and eye development, opening a new door to understanding the accelerating global phenomenon of myopia.
