Red Light Therapy Slows Nearsightedness in Kids, But Rebound Risk Found

If your child is on the verge of becoming nearsighted, a new study suggests a surprising tool might help: red light. Researchers tested repeated low-level red light therapy (RRLT) in 108 children with premyopia—eyes that are still normal but heading toward nearsightedness. Kids in the treatment group received two 3-minute sessions of red light each day, at least 4 hours apart. Over 24 months, their eyes lengthened less and their prescription changed more slowly compared to a control group. For example, the treated group's eyes grew only 0.26 mm on average, versus 0.43 mm in controls. Their nearsightedness progressed by -0.21 diopters, compared to -0.66 diopters in controls. The therapy also preserved the thickness of a layer behind the retina called the choroid, which thins in nearsighted eyes. But here's the catch: when some kids stopped the therapy, their eyes started growing faster again, and the choroid thinned more than in controls. This suggests the benefits may not last without continued treatment. The study is small and didn't report on side effects, so more research is needed. Still, for parents looking for ways to slow nearsightedness in kids, this early evidence points to a potential new option—with a warning about rebound.