Light Without the Flash: What the Evidence Says About Low-Level Light Therapy for Dry Eye

Low-level light therapy (LLLT), sometimes called photobiomodulation, uses a mask of LEDs that shines steady red or near-infrared light onto the closed eyelids, typically for about 15 minutes. Unlike intense pulsed light (IPL), there is no bright flash, just gentle warmth. It has been promoted for dry eye and meibomian gland dysfunction (MGD), and a new review in Acta Ophthalmologica, published in October 2026, pulls together the evidence on using it on its own.

What the review looked at

The authors searched four medical databases in June 2026 for studies of LLLT used alone, without IPL. They found 10 studies involving 473 people. Seven were randomised controlled trials; three were not randomised, including two with no comparison group at all. Comparators varied: sham treatment, a placebo LED, warm compresses, or IPL. Wavelengths were 625–640 nm and/or 810–850 nm, and people had between one and six sessions. Typical sessions lasted 15 minutes, with schedules ranging from four sessions in one week to six sessions spaced two to three weeks apart. Studies came from Italy, the UK, Romania, Pakistan, the USA and South Korea. Three did not study dry eye patients as such: two involved people having cataract surgery and one involved people using glaucoma drops.

Eight of the 10 studies used devices from a single manufacturer, Espansione Group.

What it found

The main analyses pooled before-and-after changes in people who had LLLT. Symptoms on the OSDI questionnaire (scored 0–100, lower is better) improved by an average of 11.42 points (95% confidence interval −14.26 to −8.57) across seven studies. Tear break-up time (NIBUT) lengthened by 1.49 seconds (0.44 to 2.54) across eight studies, and tear meniscus height rose by 0.04 mm (0.01 to 0.07).

A 95% confidence interval is the range the true effect plausibly lies in; if it doesn't cross zero, the result is unlikely to be chance alone. But before-and-after changes can't separate the treatment from natural ups and downs, placebo effects or "regression to the mean" (people often seek treatment when symptoms are at their worst). The authors themselves say these pooled figures should not be read as treatment effects compared with anything.

The more meaningful numbers come from the randomised trials that compared LLLT with a control. There, OSDI improved by 10.94 points more than control (−19.06 to −2.82) and NIBUT by 3.94 seconds more (1.64 to 6.24). For tear meniscus height, the difference from control (0.01 mm; −0.05 to 0.07) was not statistically significant, because that range crosses zero; that is not proof of no effect, but no benefit was shown.

Individual studies were mixed. One trial against a placebo LED (Park 2022) found no symptom benefit. Studies comparing LLLT with IPL pointed in different directions: one favoured LLLT on symptoms and tear meniscus height, while another, non-randomised study found IPL appeared better. No adverse events were reported.

What the studies can't tell us

• Long-term results. No study followed people for more than 3 months, and some measured results the same day.
• A clean treatment effect. The headline figures are mostly before-and-after changes, and several studies had no control group.
• Whether results apply to all devices. Eight of 10 studies used one manufacturer's devices, and the optimal settings have not been established.
• How certain the evidence is. The studies were few and small. All three non-randomised studies were at serious risk of bias, and five of the seven trials had "some concerns". An overall certainty rating was not reported.
• Review methods. The protocol was not registered in advance, and data were extracted by a single reviewer, which raises the chance of errors.
• Independence. Three authors co-own dry eye clinics in Norway that deliver talks for and/or receive financial support from several eye care and pharmaceutical companies. No link to LLLT device makers was disclosed.

Where this leaves LLLT

Overall, LLLT appears well tolerated and may help symptoms in the short term, but the evidence is early, short-term and dominated by one device brand. The review's authors suggest it may be an option for people in whom IPL-based treatment is unsuitable.

Rose Optometry in Hamilton, a DESG member practice, does not offer LLLT masks for dry eye. We share this review as evidence context, because the light-based treatment you may hear most about is often IPL, and it helps to know how different options compare. You can read more about IPL therapy for dry eye and the wider range of dry eye treatments.

Whatever the technology, the principle stays the same: treat the cause, not the symptom. A proper evaluation of your glands, tear film and eye surface is what guides the choice. Our guide to which dry eye treatment is right for you explains how that decision is made, and you can find a clinician through the list of DESG member practices.

References

• Reppe S, Subhi Y, Steinkjer T, et al. Low-level light therapy for dry eye disease and meibomian gland dysfunction: a systematic review and meta-analysis. Acta Ophthalmol. 2026. PMID: 42860563. https://doi.org/10.1111/aos.70252