Are blue light glasses effective in reducing eye strain and improving sleep quality?

Blue Light Glasses: Effectiveness for Eye Strain and Sleep Quality

Blue light blocking glasses have limited effectiveness for reducing eye strain but may provide modest benefits for sleep quality when used in the evening, particularly for those with delayed sleep phase disorder.

Effects on Eye Strain

Blue light blocking glasses appear to have minimal impact on reducing eye strain from digital device use:

• A 2023 Cochrane systematic review found that blue light filtering spectacles may not attenuate symptoms of eye strain with computer use compared to regular lenses (low-certainty evidence) 1
• There was no clinically meaningful difference in critical flicker-fusion frequency (CFF), a measure of visual fatigue, between blue light filtering and non-filtering lenses 1
• The American Academy of Ophthalmology recommends alternative strategies for reducing eye strain rather than blue light glasses 2

Better alternatives for reducing eye strain:

• Position monitor at eye level, arm's length away
• Reduce glare and reflections
• Maintain adequate humidity (>40%)
• Follow the 20-20-20 rule (look at something 20 feet away for 20 seconds every 20 minutes)
• Ensure proper refractive correction
• Increase text size and contrast
• Reduce screen brightness

Effects on Sleep Quality

Blue light glasses show more promise for sleep improvement, particularly when used in the evening:

• Blue light blocking glasses with amber or orange lenses can reduce evening melatonin suppression when used before bedtime 3
• Two weeks of evening use (from 9:00 pm until bedtime) was associated with earlier sleep onset time in adolescents and young adults with delayed sleep phase disorder 3
• In adolescent males, one week of evening use while using electronic devices was associated with less evening melatonin suppression and reduced alertness before bedtime 3
• A 2016 open-label trial found that wearing amber lenses in the evening advanced sleep onset time by 132 minutes in patients with delayed sleep phase disorder 4

However, results are mixed:

• A 2021 randomized controlled trial found that while blue light blocking glasses reduced subjective sleep onset time and awakenings, they did not improve objective measures of sleep time or quality in healthy adults 5
• A 2023 systematic review found inconsistent evidence regarding sleep quality improvement with blue light blocking glasses 1

Practical Recommendations

For those seeking to improve sleep quality:

1. Limit electronic device use 1-2 hours before bedtime when possible 2
2. If using devices before bed:
   • Reduce screen brightness (more effective than changing color temperature) 3, 2
   • Use blue light filtering glasses from approximately 2 hours before bedtime 3, 4
   • Combine blue light filtering with low-stimulation content 2

Important Considerations

• Blue light blocking glasses appear most effective for people with delayed sleep phase disorder 3, 4
• Reducing screen brightness or avoiding device use before bed appears more effective than just using blue light filtering 3, 2
• There is currently no evidence that normal screen use or LED lighting is harmful to the human retina 6
• Blue light blocking glasses are generally well-tolerated with few adverse effects, though occasional headaches, discomfort, and mood changes have been reported 1

Given the lack of associated adverse effects and ease of use, blue light blocking glasses warrant further investigation to clarify the extent of their benefits, optimal wear time, and long-term feasibility 3.