Streetlights, a hallway glow, a phone charging light, early sunrise: most of us sleep with more light than we think. Can simply blocking it help? A small sleep-lab study offers a clue.
Study at a glance
- Study: Hu RF, Jiang XY, Zeng YM, Chen XY, Zhang YH. Effects of earplugs and eye masks on nocturnal sleep, melatonin and cortisol in a simulated intensive care unit environment. Critical Care, 2010.
- Participants: 14 healthy adult volunteers.
- Design: Polysomnography (sleep-lab recording) across four conditions: adaptation, baseline, simulated ICU noise and light, and simulated noise and light with earplugs and eye masks. Urine melatonin and cortisol were also measured.
What the research shows
In this study, the simulated noise-and-light environment worsened sleep: participants had more light sleep, longer time to reach REM sleep and less REM sleep. When the same volunteers wore earplugs and eye masks in that environment, they had more REM sleep, a shorter REM latency, fewer arousals, and higher melatonin levels (P = 0.002). The authors concluded that earplugs and eye masks may promote sleep in this setting.
A later systematic review and meta-analysis in critically ill patients (Frontiers in Psychiatry, 2021) pooled 35 studies with 2,687 participants and suggested that eye masks and earplugs, alone or together, tended to improve sleep measures. A separate network meta-analysis of randomised trials reported that eye masks alone improved sleep quality compared with routine care.
Important limits: the Hu study was small, used healthy people, and simulated hospital conditions with earplugs and masks together, so it cannot isolate the effect of a mask alone or tell us what happens in a typical bedroom. The review evidence comes mostly from hospital patients, and the trials are small and varied.
Why it may work
Light reaching the eyes at night is a strong signal to the body clock. Evening and night light can suppress melatonin, the hormone linked to the sleep-wake rhythm. Blocking light with an eye mask may help keep the environment closer to true darkness, which could support natural melatonin release; the higher melatonin seen in the study is consistent with this idea, though it does not prove it.
Real-world use
Most bedrooms are not ICUs, but light intrusion is common: city lighting, shared rooms, shift work, travel, early summer sunrises or daytime naps. A mask is a simple, drug-free way to darken the sleep environment wherever you are.
Where the Gudslip Blindfold fits
The Gudslip® Blindfold is designed to block light so your eyes rest in darkness. We share the study because it illustrates the mechanism: less light at night may support a better sleep environment. It does not show that any specific product improves sleep, and results vary from person to person.
How to use it
- Put it on when you get into bed, adjusting so it sits comfortably without pressing on your eyes.
- Combine it with other basics: a cool room, a regular schedule, and dimmer lights and fewer screens in the hour before bed.
- Try it for at least a week or two; it can take time to get used to wearing a mask.
- Useful for travel, naps and daytime sleep after night shifts.
FAQ
Does an eye mask boost melatonin?
In the Hu study, melatonin was higher when volunteers used earplugs and eye masks in a bright, noisy simulated environment. That does not prove a mask alone raises melatonin at home.
Is complete darkness necessary?
Not necessarily, but lower light at night is generally considered helpful for sleep. A mask is one way to get there.
Can I use it with earplugs?
Yes. The study tested the two together. See also our article on earplugs and noise.
Who should avoid it?
If you have eye conditions, skin sensitivity, or a sleep disorder, check with a healthcare professional first.
The bottom line
A small sleep-lab study found that earplugs plus eye masks were associated with better sleep measures and higher melatonin in a light-and-noise environment. The evidence is limited, but the idea is sensible: a darker sleep environment may support better rest.
Disclaimer: This article is for general wellness information and is not medical advice. Gudslip products are not intended to diagnose, treat, cure or prevent any disease. Consult a healthcare professional about persistent sleep problems.
References
- Hu RF, Jiang XY, Zeng YM, Chen XY, Zhang YH. Effects of earplugs and eye masks on nocturnal sleep, melatonin and cortisol in a simulated intensive care unit environment. Crit Care. 2010;14:R66. PMC2887188
- The Efficacy of Eye Masks and Earplugs Interventions for Sleep Promotion in Critically Ill Patients: A Systematic Review and Meta-Analysis. Front Psychiatry. 2021;12:791342. PMC8678458