Cell Reports: Indoor Dim Lighting May Be Driving the Myopia “Epidemic”

The rapid rise of myopia (nearsightedness) worldwide is often attributed to increased screen time. However, researchers at the College of Optometry, State University of New York (SUNY), have proposed an alternative explanation: it may be the combination of prolonged near work and low indoor lighting, rather than gadgets alone. Their study was published in Cell Reports.

“Myopia has reached near-epidemic levels globally, yet we still don’t fully understand why,” said senior author Professor José-Manuel Alonso of SUNY. According to him, a key factor may be the amount of light reaching the retina during extended visual tasks indoors.

Currently, myopia — a condition where distant objects appear blurred — affects about 50% of young adults in the U.S. and Europe, and up to 90% in parts of East Asia. While genetics plays a role, the rapid increase over just a few generations suggests a strong environmental influence.

The authors propose a unifying neural hypothesis that could explain why seemingly disparate factors — from reading and smartphone use to atropine drops and outdoor exposure — influence myopia development.

“Under bright sunlight, the pupil constricts to protect the eye, but sufficient light still reaches the retina,” explained graduate student Urusha Mahardjan. “When focusing on near objects indoors — a phone, tablet, or book — the pupil also constricts to improve focus. But if lighting is dim, the amount of light reaching the retina can drop significantly.”

According to the hypothesis, prolonged near work in low light reduces retinal stimulation, which may disrupt normal visual development and accelerate myopia progression. In contrast, exposure to bright light provides more physiological stimulation.

The researchers also found that negative lenses (used to correct myopia) can further reduce retinal illumination, enhancing pupil constriction through the accommodation mechanism — the eye’s adjustment of optical power for near focus. This effect intensifies with prolonged near work and is more pronounced in already myopic individuals.

If confirmed, the findings could shift prevention strategies. To slow myopia progression, the authors suggest ensuring adequate lighting and reducing excessive accommodative load. Possible approaches include multifocal lenses, contrast-reducing techniques, atropine drops, and regular outdoor activities with distance focusing.