Red Light Therapy for Nearsightedness (Myopia): Scientific Evidence

Children with severe nearsightedness of -6 diopters or worse were randomly assigned to red light plus glasses or glasses alone in this 2025 multicenter randomized controlled trial of 202 youngsters. The red-light group used a device emitting 620- to 780 nm light for 3 minutes per session, twice a day, over a year. The front-to-back length of the eye shortened by about 0.11 millimeters with red light but grew with glasses alone, and measurable shortening occurred in 59% of the red-light group versus none of the controls, a change linked to thickening at the back of the eye.

A 2025 review surveyed the main ways to slow nearsightedness in children, from atropine drops and specialized glasses to overnight contact lenses and red light. Across the evidence it covered, red light ran at 620 to 780 nm among the newer options. Its authors concluded that red light therapy ranks among the most effective options, cutting the worsening of nearsightedness by more than 60% in the studies reviewed, while cautioning that its long-term safety still needs further proof.

Published in 2024, this clinical trial followed 44 nearsighted children aged 6 to 16 through 3 months of red light. The children used a home device emitting 620- to 780 nm light for 3 minutes per session, twice a day, 5 days a week. The blood-vessel layer beneath the retina thickened and the front-to-back length of the eye shortened slightly, a promising early sign for holding back nearsightedness. The thickening was greatest in the areas away from the center of the retina.

Red light therapy went head to head with overnight contact lenses (orthokeratology) in this 2024 retrospective study of 138 nearsighted children aged 6 to 14 followed for 2 years. Each red-light child used a device emitting 620- to 780 nm light, while the others wore the lenses nightly. With red light, the eye lengthened about 0.17 millimeters versus 0.50 millimeters with the lenses, though red light's edge appeared only slight, leaving room for prospective trials.

A 2024 observational study followed 116 nearsighted eyes on red light against untreated eyes over a year. The treated eyes had a device emitting 640- to 660 nm light for 3 minutes per session given twice a day. The front-to-back length of the eye shrank at 3 and 6 months before settling back near its starting point by 12 months, while it grew steadily in untreated eyes. Blood flow in the blood-vessel layer beneath the retina also improved throughout, which may help explain why the treated eyes shrank rather than grew.

Published in 2024, a retrospective study paired red light with various corrective lenses, including overnight contact lenses and defocus glasses, in 108 nearsighted children and adolescents over about 2 years. The red-light treatment used a device emitting 635 nm light, twice a day, added to whichever lenses each child wore. The study found that red light combined with these lenses slowed the worsening of nearsightedness compared with a control group.

100 nearsighted children whose eyes kept lengthening despite overnight contact lenses (orthokeratology) were studied after adding red light in this 2024 retrospective study. The added treatment was a device emitting 640- to 660 nm light for 3 minutes per session, twice a day, over a year, alongside continued lens wear. Adding red light slowed the lengthening of the eye beyond what the lenses alone had achieved, with older children among these poor responders seeming to gain the most.

In 2024, a randomized controlled trial split 73 nearsighted children and adolescents aged 6 to 14 between red light added to their glasses and glasses alone. The treated group used a device emitting 620- to 780 nm light at 0.9 mW over 6 months. After 6 months, focusing error had barely shifted in the red-light group but worsened noticeably with glasses alone, suggesting red light can hold nearsightedness in check, with no adverse reactions seen.

Layering repeated low-level red-light therapy (RLRL) on top of overnight contact lenses (orthokeratology) was tested against the lenses alone in this 2024 multicenter randomized controlled trial of 47 nearsighted children aged 8 to 13. The combination group used a device emitting 620- to 780 nm light for 3 minutes per session, twice a day, over a year, on top of nightly lens wear. Over 12 months, the front-to-back length of the eye barely changed with the combination but grew about 0.27 millimeters with lenses alone. The pairing appeared to be a stronger option, with children still seeing well during the day.

336 nearsighted children took part in this 2024 clinical trial of a head-mounted red-light device, assessed after 3 months. The children used the device emitting 650 nm light for 3 minutes per session, twice a day, over the 3 months. The front-to-back length of the eye shrank by about 0.03 millimeters on average, and focusing error eased slightly, with the effect looking stronger in older children and those more nearsighted to begin with, and no obvious side effects.

Zhu and colleagues followed 108 nearsighted children on red light or a control group over a year in this 2024 randomized controlled trial, tracking retinal function and structure. The treated children used a device emitting 620- to 780 nm light across the year, with retinal tests at 6 and 12 months. The authors concluded that red light was safe across 12 months, with the eye staying shorter and focusing error milder than in controls, while noting a change in 2 retinal reflectance measures that they said warrants further watching.

5 studies covering 685 nearsighted children were pooled in a 2024 systematic review from Brazil. Across the pooled studies, red light was run at 620 to 780 nm for about 3 minutes per session, with follow-up from 6 months to a year. According to the combined results, red light led to less worsening of focusing error and eye lengthening than control care with no clear rise in side effects, though the authors said longer-term and head-to-head comparisons are still needed.

Eye shortening was recorded in 85% of 342 nearsighted children a month into red light, in this 2024 retrospective study of children aged 4 to 13. The children used a device emitting 640- to 660 nm light for 3 minutes per session, twice a day, with follow-up from 6 months to a year. The average reduction in the front-to-back length of the eye built up the longer treatment continued and was larger in older children with longer eyes, though as a look-back study it lacked an untreated comparison group.

A 2024 randomized clinical trial assigned 336 nearsighted children, average age 9, to daily red light or a control group. The treated children used a device emitting 650 nm light for 3 minutes per session, twice a day, over a year. Over 12 months, focusing error and the front-to-back length of the eye changed far less with red light than without it, and masked review of retinal photographs found no signs of harm.

5 randomized controlled trials in 833 nearsighted children were combined in a 2024 systematic review of red light. Across the pooled trials, red light was run at 650 nm for about 3 minutes per session, twice a day, with follow-up from 3 months to a year. According to the pooled results, the front-to-back length of the eye grew less and focusing error worsened less with red light than with single-vision glasses at every point. However, the authors flagged that long-term effects remain unknown.

94 children with early signs of nearsightedness took part in this 2024 randomized trial of red light against a control group, with follow-up over a year. The treated children used a device emitting 640- to 660 nm light for 3 minutes per session, twice a day, across the year. The blood-vessel layer beneath the retina appeared to thicken across the whole central retina with red light while thinning in the control group, a change linked to less worsening of focusing error and eye growth.

Powers of 0.37, 0.60, and 1.20 mW were tested against a control group in 200 nearsighted children in this 2024 randomized controlled trial. All groups used 650 nm light for 3 minutes per session, twice a day, over 6 months. Every level slowed the worsening of focusing error and eye lengthening, an effect that appeared to hold across a range of doses, with the thickening of the eye's blood-vessel layer greatest at the highest power.

A 2023 modeling study compared the cost and benefit of several nearsightedness treatments in children over a 5-year horizon, including red light, atropine drops, special glasses, and overnight contact lenses. Red light at 620 to 780 nm was weighed against single-vision lenses as the baseline. The authors concluded that low-dose atropine and outdoor time were the most cost-effective, and that red light, though pricier at about 846 US dollars per unit of focusing error saved, could still be worthwhile.

Drawing on studies of 1,608 nearsighted patients, a 2023 review traced how red light might slow the condition. Across those studies, wavelengths ranged from 624 to 810 nm, most delivered for about 3 minutes a session. The review concluded that red light appears effective at controlling both the onset and progression of nearsightedness, likely by raising cell energy and repair in the eye, though as a narrative review it stopped short of pooling the numbers into a single estimate.

7 randomized controlled trials covering 1,031 nearsighted children aged 6 to 16 were pooled in a 2023 meta-analysis. Across the pooled trials, red light was delivered at wavelengths from 620 to 780 nm, with treatment lasting 6 months to a year. According to the pooled results, red light was linked to a shorter front-to-back length of the eye and less focusing error than control treatments, including in children compared against overnight contact lenses or low-dose atropine.

When researchers re-examined a 2023 randomized trial, they followed how the blood-vessel layer beneath the retina changed in 143 nearsighted children on red light or single-vision glasses. The red-light group used a device emitting 620- to 780 nm light over a year. The re-analysis found that every measured part of this layer, including its blood vessels, enlarged over 12 months with red light while shrinking in the glasses group.

In 2023, a clinical trial followed 67 nearsighted children aged 8 to 11 given red light over about 4 weeks. The treated children used a device emitting 650 nm light for 3 minutes per session, twice a day. The blood-vessel layer beneath the retina thickened and its blood flow rose over time, an effect that seemed to build up gradually the longer treatment continued, while the retina itself showed no measurable change.

New nearsightedness developed in only 1.8% of children given red light over 6 months, against 12.5% of untreated children, in this 2023 randomized controlled trial of 112 youngsters aged 6 to 12. The treated children were irradiated with 650 nm light for 6 minutes a day across the 6 months. The front-to-back length of the eye also seemed to hold steady rather than growing, and no adverse events were recorded.

Children given red light were about a third less likely to become nearsighted over a year than untreated children, in this 2023 randomized trial of 278 youngsters, average age 8, with early signs of myopia. The red-light group used a device emitting 640- to 660 nm light for 3 minutes per session, twice a day, 5 days a week for a year. According to the trial, 40.8% of the red-light group developed nearsightedness against 61.3% of controls, and the eye lengthened, and focusing error worsened less with treatment, with no damage seen on eye scans.

164 nearsighted schoolchildren in Shenzhen took part in this 2023 clinical trial of home red-light devices, with separate groups for milder and more severe nearsightedness alongside a glasses group. The red-light groups used devices emitting 650 nm light, with follow-up on average about 2 months in. At the end, the researchers reported that the front-to-back length of the eye shrank slightly in both red-light groups but grew in the glasses group, an effect they read as meaningful even in more severe cases.

A 2023 randomized controlled trial followed 39 nearsighted children aged 8 to 12 over a year of red light against single-vision glasses. The treated children used a low-intensity laser emitting 640 to 660 nm light for 3 minutes per session, twice a day, across the year. The treated eyes grew more slowly and in some cases shortened, appearing to run counter to the older view that eye lengthening cannot be reversed.

Children given red light were compared with untreated controls in this 2023 post-hoc analysis of a randomized trial in 264 nearsighted children aged 8 to 13. The red-light group used a device emitting 640- to 660 nm light for 3 minutes per session, twice a day, 5 days a week for a year. Eye shortening of more than 0.05 millimeters occurred in about 22% of the red-light group but almost never among controls. The researchers also found that thickening of the blood-vessel layer explained only part of the change.

More than a quarter of 434 nearsighted children aged 3 to 17 showed a measurable shortening of the eye after red light, in this 2023 retrospective multicenter analysis. The children had used a home device emitting 650 nm light for at least a year. The average change worked out to a reduction of 0.142 millimeters a year, with the largest shortening among younger children who had started with longer eyes.

In 2023, a randomized controlled trial followed 120 nearsighted children given red light or single-vision glasses to see how the blood-vessel layer beneath the retina changed. The red-light group used a home device emitting 650 nm light for 3 minutes per session, twice a day, over a year. This layer thickened steadily throughout red-light treatment while thinning with glasses, and its change at 3 months alone appeared to predict how well nearsightedness was controlled at 12 months.

A 2023 randomized, double-blind trial pitted full-power red light against a sham device at 10% of that power in 111 nearsighted children. The red-light group used a desktop device emitting 650 nm light for 3 minutes per session, twice a day, over 6 months. According to the trial, focusing error and the front-to-back length of the eye changed less with full-power red light than with the dimmed device. No treatment-related adverse events were reported.

Over a year, the front-to-back length of the eye grew just 0.01 millimeters in nearsighted children given red light, against 0.39 millimeters in those wearing single-focus glasses, in this 2023 randomized controlled trial of 86 children aged 6 to 13. The red-light group used a device emitting 635 nm light for 3 minutes per session, twice a day, across the year. Focusing ability also held steadier with red light, though when treatment stopped for 3 months the children showed a slight return of nearsightedness.

98 nearsighted adults, most in their twenties, took part in this 2022 randomized controlled trial of red light against an untreated control group. The treated adults used a device emitting 650 nm light for 3 minutes per session, twice a day, over about 4 weeks. A single month of red light shortened the front-to-back length of the eye while thickening the blood-vessel layer beneath the retina and improving its circulation, with the change appearing to come mainly from the back of the eye rather than the front.

Red light went head to head with low-dose atropine eye drops in this 2022 randomized controlled trial of 60 nearsighted children aged 7 to 15. The red-light group used a device emitting 650 nm light for 3 minutes per session, twice a day, over about a year, while the other group used 0.01% atropine drops. The front-to-back length of the eye grew 0.08 millimeters with red light versus 0.33 millimeters with the drops, and focusing error held steadier too. However, both were single-center findings that may need wider testing.

224 nearsighted children aged 6 to 12 took part in this 2022 randomized trial of red light against a control group. The treated children used a device emitting 650 nm light for 3 minutes per session, twice a day, over 6 months. The front-to-back length of the eye shortened slightly with red light but grew in the control group, and far more treated children showed a shift toward farsightedness, a sign of slower nearsightedness. No side effects seen in the short term.

2022 brought a review that gathered the published evidence on red light for nearsightedness. Across the studies it covered, red light spanned wavelengths from about 614 to 670 nm, with sessions of a few minutes given up to twice a day and treatment lasting from about 2 weeks to 6 months. Its authors concluded that red light can shift the eye toward farsightedness and so may help prevent and control nearsightedness, and reported that it appeared gentle on the cornea and retina at the cellular level.

In 2022, a retrospective study of 161 nearsighted children in eastern China compared red light against single-vision glasses. The treated children used a home device emitting 635 nm light for 3 minutes per session, twice a day, over 9 months. The front-to-back length of the eye shortened slightly in the red-light group but grew in the glasses group, and the blood-vessel layer beneath the retina thickened. The authors suggested that it reflects slower nearsightedness, while noting that randomized trials are still needed.

Jiang and colleagues randomly assigned 246 nearsighted children aged 8 to 13 to repeated low-level red-light therapy (RLRL) or ordinary single-vision glasses in this 2022 randomized controlled trial. Children in the red-light group used a home device emitting 650 nm light for 3 minutes per session, twice a day, 5 days a week for a year. The researchers reported that over 12 months, the front-to-back length of the eye grew 0.13 millimeters with red light versus 0.38 millimeters with glasses, alongside a smaller rise in focusing error and no serious adverse events.

A 2021 clinical trial in Taiwan tested low-level laser at acupuncture points on the ear in 49 nearsighted teenagers, average age 16. Each teenager received a single 30-minute session of 830 nm laser during a class break, with focusing measured before and after. The single session appeared to restore the eyes' focusing ability faster than simply resting them, with a slightly larger easing of focusing error among the treated teenagers.

Red light therapy went head to head with overnight contact lenses (orthokeratology) in this 2021 randomized controlled trial of 229 nearsighted children, set against a third group in ordinary single-vision glasses. The red-light group used a device emitting 650 nm light for 3 minutes per session, twice a day, over 6 months. The children using red light showed less lengthening of the eye than both the contact-lens and the glasses groups, though the follow-up was short.

88 children aged 6 to 14 took part in this 2009 clinical trial of low-intensity infrared laser for worsening nearsightedness. 66 children with progressive nearsightedness received the infrared laser at 780 to 1400 nm, aimed at the eye region to improve its blood supply, while 22 children without vision problems served as a comparison group. Nearsightedness appeared to stabilize in 78.8% of the treated children, an outcome that could help hold back the condition in young patients.

20 safety studies covering 2,380 nearsighted people aged 3 to 18 were gathered in a 2024 systematic review of red light. Across the studies, red light ran at 620 to 780 nm, with follow-up reaching about 2 years. According to the review, no permanent vision loss or structural eye damage turned up. The most common effect was a brief afterimage clearing within 6 minutes, and 2 case reports of reversible vision decline resolved months after stopping, though the authors urged longer safety studies.

Red light went head to head with near-infrared light in this 2024 clinical trial of 30 young adults in Switzerland. Each subject had 1 eye exposed for 10 minutes to either red light at about 620 nm or near-infrared light at about 875 nm, set 50 centimeters away, with the front-to-back length of the eye measured before and after. Red light shortened the eye in most non-nearsighted subjects while near-infrared light did not, hinting that the benefit depends on visible light rather than heat alone, with only about 41% of already-nearsighted eyes responding.

In 2024, a clinical trial followed 40 nearsighted school-age children aged 7 to 14 given red light over 6 months. The children used a device emitting 620- to 780 nm light, with retinal structure checked at 1, 3, and 6 months. The central retina thickened within a month and then held steady, and the tiny vessels supplying it showed no meaningful change, a reassuring sign for safety. However, this study looked only at retinal structure rather than whether nearsightedness slowed.

Pooling 13 studies of 1,857 nearsighted children and adolescents, a 2023 systematic review examined red light therapy. Across the pooled studies, wavelengths ran from 620 to 780 nm, and 8 studies could be combined for the main analysis. Red light was tied to markedly less worsening of focusing error than in control groups, though the certainty of the evidence was rated low, leaving room for larger trials with longer follow-up.

Yang and colleagues tested the immediate effect of a single red-light session in 25 nearsighted children in this 2023 clinical trial. 1 randomly chosen eye received 650 nm light for 3 minutes, with retinal blood flow measured before, 5 minutes after, and an hour later. Blood flow at the center of the retina appeared to rise briefly before returning to normal within an hour, while the blood-vessel layer beneath the retina showed no measurable change, offering only partial, short-term support for how red light might work.