Blue light is part of the visible spectrum, present in vastly different amounts in daylight and in our screens. This page explains what it is, where it comes from, and what a filtering lens actually does. To find out whether a filter might be useful in your case, our detailed article on the effectiveness of blue-light filtering glasses reviews the available studies.
1. What is blue light?
The light visible to our eyes spans wavelengths from 380 to 780 nanometres. Blue light corresponds to the range between 380 and 500 nanometres. It is generally divided into two parts:
- blue-violet light, between 380 and 455 nm;
- blue-turquoise light, between 455 and 495 nm, which plays a role in regulating our biological clock and sleep-wake cycle.
2. Where does the blue light you receive come from?
By far, the primary source is daylight. The sun emits an amount of blue light that dwarfs that of any screen. Next come artificial lighting sources: the cooler and whiter a light, the more blue light it emits; the warmer or more orange, the less. Screens are relatively cool light sources, but of low intensity compared to the sky.
What sets screens apart is not the quantity of blue light, but the timing of exposure: late in the evening, and at close range to the face.
3. What we know about its effects
On the retina. The Cochrane review of 18 August 2023 was unable to conclude on the effect of filtering lenses on macular health: none of the 17 trials included had measured this outcome. Experimental studies on cells and animals exist, but they do not allow conclusions for normal screen use. The INRS indicates that emission levels from standard screens do not represent a retinal risk under the conditions it describes. We therefore do not present our lenses as protection against macular degeneration.
On sleep. Here, the effect of light itself is real: exposure in the evening can suppress melatonin secretion and delay sleep onset. That does not mean wearing filtering glasses in the evening solves the problem: we detail this in our article on blue light and sleep.
On visual fatigue. The discomfort felt after hours in front of a screen is real, but it has several possible causes: reduced blinking, dry eyes, glare, a poorly positioned screen, or inadequate prescription. Available studies do not show that blue-light filters reduce this fatigue. Our guides on filter effectiveness and on settings for gaming and screen work review the data and the measures that do work.
4. What exactly does a filtering lens do?
A blue-light filter lens allows a reduced amount of light to pass through a portion of the spectrum. The approach we adopt is to filter mainly blue-violet light and allow blue-turquoise light to pass, so as not to distort colour perception or disrupt regulation of the sleep-wake cycle.
According to our lens specifications, filtration is approximately 30% of blue light. This is a technical characteristic of the lens, and it should be read for what it is: a percentage of filtration is not a percentage reduction in fatigue. No data allow converting one into the other.
A filter does not correct vision, and it does not do the same job as an anti-reflective coating: one acts on part of the transmitted light, the other reduces reflections on the lens surface. Our guide to choosing your lenses details these differences.
5. Receiving your blue-light filtering glasses
All our non-prescription frames, excluding sunglasses, are delivered by default with blue-light filter lenses, at no extra cost and with nothing to select. For prescription lenses, blue-light filter and anti-reflective treatments are available as options at checkout, along with thinned lenses tailored to your prescription.
Discover all our blue-light filtering frames or our full range of prescription glasses. Unsure what you need? Our qualified opticians are on hand to advise you in one of our 17 stores.
Frequently asked questions about blue light
Is blue light from screens harmful to the eyes?
For standard screens, the INRS indicates that emission levels do not represent a retinal risk under the conditions it describes, and the 2023 Cochrane review was unable to assess an effect on macular health due to a lack of trials measuring it. The discomfort felt in front of a screen is real, but it stems from visual fatigue, not from damage.
Are blue-light filtering glasses effective?
Available studies do not show a proven benefit for visual fatigue, and the effect on sleep remains uncertain. Some people report improved comfort, which does not isolate the contribution of the filter from that of the prescription and anti-reflective coating. We detail all this in our article on the effectiveness of blue-light filtering glasses.
What can you do to limit blue light in the evening?
Lower the brightness of the screen and the room, prefer warm lighting, and ideally stop using screens an hour before bedtime. These habits count for more than any accessory.
Can children wear blue-light filtering glasses?
There is nothing against it in terms of safety, but no data support presenting this filter as useful or necessary for children. For a child, the priority is regular eye examinations and an up-to-date prescription.
How do you get blue-light filtering glasses?
All our non-prescription frames are delivered with blue-light filter lenses. Browse our blue-light filtering collection and try them on using our virtual try-on.
Sources
- Singh S, Keller PR, Busija L et al. Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews, 18 August 2023, CD013244. Summary and limitations.
- INRS. Travail sur écran : risques pour la santé. Dossier.
- Assurance Maladie. Comment mieux dormir à l'âge adulte ?
Page reviewed by Elie Attias, qualified optician, director and co-founder of Le Petit Lunetier. Updated 24 September 2026.