Do blue light glasses really work?
By See Better · Updated · 5 min read
The short answer
The best current evidence says blue light glasses make little or no difference to eye strain from screens, and there is no good evidence that they protect the health of your eyes. Tired eyes at a screen come from blinking less and focusing up close for hours. Regular breaks and an up-to-date prescription help far more.
Key points
- A 2023 review of the research found blue light lenses probably do not reduce screen eye strain.
- Screens give off far less blue light than daylight does.
- Screen eye strain is caused by reduced blinking and long periods of close focus.
- Breaks, good screen set-up and the right prescription are what make a difference.
What blue light is
Blue light is part of ordinary visible light. The sun is by far the biggest source of it, which is why the sky looks blue. Phones, laptops, tablets and LED bulbs also give off blue light, but in very small amounts compared with being outdoors, even on a cloudy day.
Blue light glasses have lenses with a coating or a faint tint that filters out part of this blue light. They are sold with three promises: less eye strain at screens, better sleep and long-term protection for the retina.
What the research says
In 2023 the Cochrane collaboration, an independent group that reviews medical evidence, analysed 17 clinical trials of blue light filtering glasses. Its conclusions were:
- Eye strain: blue light lenses probably make little or no difference to eye strain from computer work compared with ordinary lenses.
- Sleep: the evidence is unclear. Some small studies found a benefit and others found none.
- Eye health: there was no evidence from the trials that the lenses protect the retina.
The studies were small and short, so the picture may change with better research. For now, the claim that blue light glasses relieve tired eyes is not supported by good evidence.
Why screens make your eyes tired
If blue light is not the problem, what is? Three things:
- You blink less. People blink roughly a third as often when they concentrate on a screen. The surface of the eye dries out, which causes burning, grittiness and blur.
- Your focusing muscles do not rest. Holding focus at a short distance for hours is tiring, in the same way that holding your arm out is tiring.
- Your prescription or set-up is slightly off. A small uncorrected prescription, glare on the screen, or a monitor that is too close or too high all add strain.
None of these is fixed by filtering blue light.
What actually helps
- Follow the 20-20-20 rule. Every 20 minutes, look at something 6 metres away for 20 seconds. See digital eye strain and the 20-20-20 rule.
- Blink on purpose, and use lubricating eye drops if your eyes feel dry. See dry eyes: causes and relief.
- Set up your screen properly. Keep it about an arm's length away, with the top of the screen at or just below eye level.
- Cut the glare. Avoid a bright window behind or in front of the screen. An anti-reflective coating on your lenses reduces reflections.
- Have your eyes tested. If you have not had an eye test in the last two years, an out-of-date prescription may be the real cause.
Blue light and sleep
Bright light in the evening, including screen light, can delay the hormone that makes you sleepy. Whether blue light glasses fix this is uncertain. Habits with better evidence are free: dim the lights in the hour before bed, switch your devices to night mode, and put the phone down 30 to 60 minutes before you want to sleep.
Is blue light from screens damaging my eyes?
There is no good evidence that the blue light from phones and computers damages human eyes. The amount is tiny compared with sunlight. For protecting your eyes from light, what matters is ultraviolet (UV) from the sun, and that is a job for proper sunglasses.
So should you buy them?
Blue light lenses are not harmful, and some people find the slightly warmer tint pleasant. If they are included at no cost, or you simply like them, there is no reason to avoid them. Just do not expect them to cure tired eyes, and do not pay much extra for them in the hope that they will. Put the money and effort into an accurate prescription and better screen habits first.
Frequently asked questions
Do blue light glasses help with headaches?
There is no good evidence that they do. Headaches at a screen are more often caused by eye strain from an uncorrected prescription, glare, poor posture or long sessions without a break. An eye test can rule out the first of these.
Are blue light glasses bad for your eyes?
No. They are safe to wear. The question is only whether they do anything useful, and the current evidence suggests they do very little for eye strain.
Should children wear blue light glasses?
There is no evidence that children need them. More outdoor time, regular screen breaks and sensible limits on screen time do more for children's eyes. See screen time and children's eyes.
What is the difference between blue light glasses and computer glasses?
Blue light glasses filter some blue light. Computer glasses have a prescription set for screen distance, so your eyes do less focusing work. For people over 40 in particular, properly prescribed computer glasses can make a real difference.
This article is general information and is not a diagnosis or a substitute for an eye examination. If you are worried about your eyes or your sight, see an optometrist or a doctor. Sudden loss of vision, eye injuries and severe eye pain are emergencies.
