Overview
What is it?
Blue-light filtering, or blue-light blocking, glasses are specially designed lenses that filter out ultraviolet radiation and varying portions of short-wavelength visible light (blue light) from reaching the eyes. They are commercially available and are claimed to improve visual performance, provide retinal protection, and promote better sleep quality by reducing exposure to blue light, especially in the evening.
How does it work?
Blue light glasses work by reducing the transmission of short-wavelength visible light, particularly blue light, which is known to affect the body's circadian rhythm. Blue light exposure, especially from digital devices in the evening, can suppress the production of melatonin, a hormone that regulates sleep. By filtering out blue light, these glasses help minimize sleep and circadian rhythm disruption, making it easier to fall asleep and stay asleep.
What are the benefits?
The primary benefit of blue light glasses is their potential to improve sleep quality by reducing exposure to blue light, particularly in the evening. They may help with sleep onset latency (the time it takes to fall asleep) and overall sleep quality, especially for individuals who use digital devices before bed. Additionally, they may provide some protection against retinal damage caused by prolonged exposure to blue light.
Effectiveness
What does the research say?
Research on the efficacy of blue light glasses for improving sleep has shown mixed results. Some studies report significant improvements in sleep quality and reduced sleep onset latency, particularly for individuals with sleep disorders, jet lag, or shift work schedules . However, other studies have found no significant difference in sleep outcomes when using blue light glasses compared to non-filtering lenses. The evidence is considered low-certainty due to variability in study designs and populations .
Side Effects
Increased depressive symptoms
Some users have reported increased depressive symptoms, though this is rare and the evidence is not conclusive .
Headache
Headaches have been occasionally reported by users of blue light glasses, possibly due to prolonged use or improper fit .
Discomfort wearing the glasses
Discomfort while wearing the glasses, such as pressure on the nose or ears, has been noted by some individuals .
Lower mood
A few users have experienced lower mood or mild emotional discomfort, though this side effect is not well-documented and may vary by individual .
Evidence
Clinical Studies & Trials
[1] Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults.
This review examines the effects of blue-light filtering lenses on visual performance, sleep, and retinal health. It found mixed evidence on sleep improvement, with some studies showing benefits and others showing no significant difference.
View study[2] Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review.
This systematic review evaluates the use of blue-blocking glasses for sleep and mood disorders. It found substantial evidence supporting their effectiveness in reducing sleep onset latency, particularly for individuals with sleep disorders or irregular schedules.
View study[3] The effect of blue-light blocking spectacle lenses on visual performance, macular health and the sleep-wake cycle: a systematic review of the literature.
This review investigates the benefits and potential harms of blue-light blocking lenses, including their effects on sleep quality and circadian rhythm. It highlights the need for more high-quality studies to confirm their efficacy.
View study[4] The effects of blue-light filtration on sleep and work outcomes.
This study explores how blue-light filtering glasses improve sleep quality and work-related outcomes. It found that wearing these glasses can enhance sleep quantity and quality, leading to better work engagement and performance.
View study