Global rates of myopia, or short-sightedness, are climbing rapidly. New research from the State University of New York (SUNY) College of Optometry points to modern indoor habits as a significant factor, potentially overriding the focus solely on screen time.
The study involved lab tests on volunteers with and without myopia. Researchers observed that activities requiring close-up viewing, termed "near work," may contribute to short-sightedness due to how the pupil constricts to manage light entering the eye.
"Myopia has reached near-epidemic levels worldwide, yet we still don't fully understand why," stated visual neuroscientist Jose-Manuel Alonso. "Our findings suggest that a common underlying factor may be how much light reaches the retina during sustained near work - particularly indoors."
Key observations revealed that contrast plays a more critical role than brightness in eye movements and pupil constriction during near work. In individuals with myopia, eyes tend to turn inward more, and pupils constrict further, potentially weakening the retina's "ON pathway," which processes light.
This leads to a hypothesis that in myopia, focus is prioritized over brightness, creating a feedback loop that exacerbates the condition. This issue is amplified in dimmer indoor environments where retinal illumination can be significantly reduced.
While a strong genetic component exists, researchers suggest that light loss, not just blurry vision, may trigger or worsen myopia. Corrective lenses that are too strong could also be problematic by reducing light exposure.
This research, though based on a limited sample and requiring further investigation, offers a new perspective on myopia prevention and treatment. With nearly 40 percent of young people projected to be short-sighted by 2050, understanding these physiological mechanisms is critical.
"More research is needed, but it gives us a new way to think about prevention and treatment," Alonso added.