Study finds steam-warming eye masks provide short-term ocular comfort in children with premyopia, myopia

A single-arm study conducted at Shanghai Aier Puliang Eye Hospital evaluated the short-term effects of a steam-warming eye mask on ocular parameters in children with premyopia or myopia, reporting changes in choroidal perfusion, visual function, and subjective symptoms following a 20-minute intervention. The study was led by first author Kemeng Gao, PhD, of Personal Health Care Lab, Kao (China) Research and Development Centre Co Ltd in Shanghai, China and was published in Clinical and Experimental Optometry.¹

“The steam-warming eye mask showed significant enhancements in ocular comfort, visual function, and choroidal perfusion in children,” the study authors stated. “This intervention appears to be a promising tool for managing ocular health in pediatric populations, especially in the context of myopia prevention and control.”

The study was carried out between July 8 and August 1, 2024, and included 127 eyes from 68 children aged 8–14 years. Participants were classified as having preclinical myopia or myopia based on spherical equivalent refraction. Baseline assessments included optical coherence tomography angiography, visual function testing, dry eye evaluation, and subjective symptom scoring. The intervention involved a single 20-minute application of a commercially available steam eye mask, followed by repeat measurements.¹

Following the intervention, choroidal perfusion area increased significantly, with reported differences ranging from 0.001 to 0.019 mm² (p<0.05). The effect was more pronounced in regions farther from the macular fovea, while areas closer to the macula showed limited change. Increases were also observed in specific nasal regions, including N-1–9 mm, N-3–9 mm, and N-6–9 mm.¹

Visual function measures showed improvement after treatment. Amplitude of accommodation increased by a mean of 1.00 D, representing a 13.9% relative improvement (p<0.001). Uncorrected distance visual acuity improved, with median logMAR values changing from 0.15 to 0.1 (p<0.001). Tear film break-up time increased by a mean of 1.45 seconds, corresponding to a 25.26% improvement (p<0.001). No statistically significant changes were observed in axial length, spherical equivalent refraction, or astigmatism measures.¹

Subjective symptom assessments indicated reductions in eye strain, dryness, and soreness, along with increased relaxation scores. Eye strain scores decreased from a median of 24 to 0 (p<0.001), and dryness scores decreased from 13.5 to 0 (p<0.001). Soreness also declined, while no meaningful changes were observed for gritty sensation or eye congestion.¹

A negative correlation was identified between amplitude of accommodation and choroidal perfusion area (r = −0.185, p<0.05). Mixed-effects analysis accounting for inclusion of both eyes suggested a greater effect in the left eye.¹

“A binocular mixed effects analysis was performed on the choroidal blood flow perfusion area in areas with significant differences. The left eye having better data than the right eye. When blood flow testing was conducted, the right eye was always measured first. The difference could be due to the slight tension in the blood vessels of subjects caused by the removal of the eye mask, which led to vasoconstriction. The data improved after relaxation later on, or perhaps it was due to the delayed effect of the intervention. It will have to be clarified in future studies,” the study authors stated.

The authors reported that the intervention was associated with improvements in ocular comfort, tear film stability, and certain visual function parameters, while noting no measurable changes in refractive error or axial length. They stated that the observed effects are functional and symptomatic rather than structural.¹

The study also identified several limitations, including the absence of a control group and the short duration of follow-up, which limit conclusions regarding causality and long-term effects. The authors noted that further randomized controlled trials with larger sample sizes and longer follow-up are needed to evaluate sustained outcomes.¹

“While the sample size was sufficient for detecting significant changes in subjective symptoms and visual function, the study primarily focused on short-term outcomes,” researchers stated.

The findings were discussed in the context of increasing global prevalence of myopia and interest in early interventions during the preclinical phase, as well as prior research suggesting that thermal therapies may influence ocular circulation and visual comfort.¹

Reference:

1. Gao K, Xu Y, Siata Y, Liu H, Cai M, Xing G. Effects of steam warming eye masks on choroidal perfusion, visual function, dry eye measures, and symptoms in children with myopia. Clin Experiment Optom. 2026. 1–9. https://doi.org/10.1080/08164622.2026.2631765