Do blue light glasses help? What the research says

Blue light glasses, or lenses with a blue light filter, are often sold as a way to reduce eye strain from screens, sleep better and protect the eyes. It's a reasonable thing to wonder about if you spend most of the day looking at a monitor or phone.

In 2023, Cochrane, an organisation that reviews medical research, published an updated review of the trials on these lenses. It's the most thorough look at the question so far.

What the review looked at

• 17 randomised controlled trials with 619 adults in total
• Trial sizes from 5 to 156 people
• Follow-up from less than a day to five weeks

The trials were too different from one another to combine into one result, so the reviewers described the findings in words rather than as a single number.

Eye strain

This is the main reason most people buy them. The review found that blue light filtering lenses may make little or no difference to eye strain from computer work in the short term. The certainty of this evidence was rated low, which means future research could change the picture, but there is no good evidence of a benefit right now.

The American Academy of Ophthalmology points in the same direction. In its advice on screen time, it reports that blue light filters were no more effective at reducing symptoms of digital eye strain than a neutral filter.

Sharpness of vision

The review found the lenses probably make little or no difference to how sharply you see, based on one study.

Sleep

The evidence here is mixed. Of six trials that asked about sleep, three reported better sleep scores with the lenses and three found no clear difference. The certainty was rated very low, so the reviewers could not say whether the lenses help sleep.

Protecting the back of the eye

None of the included trials measured the health of the macula (the central part of the retina). The review could not draw any conclusion about whether the lenses protect the eye.

Side effects

Reports were sparse. Some people described headache, low mood or discomfort wearing the glasses, but similar effects were also seen with standard lenses. The review describes them as temporary and generally mild.

What eye care bodies say

After the review, the College of Optometrists in the UK said there may be no short-term advantage to blue light filtering lenses for visual fatigue, and that there is no strong evidence they improve visual performance. It also reminded optometrists to tell patients when a product isn't supported by evidence.

What to try instead

If your eyes feel tired at the screen, habits with more support are a better starting point:

• Regular breaks, such as the 20-20-20 rule
• Blinking fully during breaks
• A screen at about arm's length, slightly below eye level
• Less glare, and screen brightness that matches the room
• An up-to-date eye test, so your glasses or contacts suit the distance you work at

Our guide to screen eye strain goes through these in more detail.

If you already wear them

There's no need to throw them away if you like them. The review found no strong evidence of harm. Just don't rely on them in place of breaks or an eye test, and don't assume they protect your eyes from damage, because that hasn't been shown.

When to see someone

See an optometrist or eye doctor if:

• Eye strain or headaches keep coming back despite breaks
• You need to lean in or squint to read the screen
• Your vision is blurry and doesn't clear when you rest

A short note of when symptoms happen and what you were doing makes the appointment easier. Our guide on what to tell your eye doctor can help.