Blue light filter glasses: What they can do – and what they can’t

Briefly upfront: A blue light filtering glasses lens lets less blue light pass through the glass. How much less is stated in the test report, not on the packaging. That it prevents tired eyes, headaches or sleep problems is not scientifically proven. A large Cochrane Review evaluated all available studies in 2023 and found no clear short-term benefit against screen-related fatigue.

In this article, we look at what research actually says, what actually helps with burning eyes, and how you read a data sheet so that no one sells you a number that isn't correct.

And yes, we sell blue light filtering glasses ourselves. That's exactly why we follow one rule: Measured, not claimed. Everything written here is linked. You can verify it yourself.

What is blue light anyway?

Visible light ranges approximately from 380 to 780 nanometers (nm) wavelength. The short-wave part between about 380 and 500 nm appears blue to blue-violet. This is exactly the range referred to when "blue light transmittance" is mentioned in a test report. Below 380 nm begins invisible UV light.

Important for classification: Blue light is not just a screen-related issue. By far the largest source is the sun. This is also emphasized by the American Academy of Ophthalmology (AAO): Screens emit far less blue light than we get from the sun outdoors.

The Deutsche Ophthalmologische Gesellschaft (DOG) named concrete numbers in 2021. In its press release "No need to worry: LED displays are not a danger to eyes or sleep" it compares the illuminance of various light sources:

Light source	Illuminance
Computer screen, very bright, 50 cm distance	under 500 lux
Covered winter day outdoors (Germany)	approx. 5,000 lux
Sunny day outdoors	up to 100,000 lux

Source: DOG press release from September 13, 2021 via idw.

A gray November day outdoors thus provides about ten times as much light as a very brightly adjusted monitor. That does not mean screen light plays no role: in the evening, light can affect your internal clock. We have written a separate article about this: Blue light, screen time and sleep: What research says. For the question "Does screen light harm my eyes?", the scale is critical.

Do blue light filtering glasses make tired eyes fit again? This is what research says

The most important source for this question is the Cochrane Review by Singh et al. (2023). Cochrane Reviews are considered particularly thorough: they do not look at a single study, but compile all available randomized controlled studies (RCTs) on a question and evaluate their quality.

The result in short:

• 17 RCTs with 5 to 156 participants were included. The durations ranged from less than one day to five weeks.
• There may be no difference in subjective eye fatigue between blue light filtering lenses and normal lenses (low reliability of evidence).
• There is likely little or no difference in visual acuity.
• The review says it cannot be determined whether filtering lenses affect sleep. The evidence is very uncertain.
  

The authors also point out that many of the studies were small and methodically vulnerable. "No effect found" does not mean "effect is safely excluded". But it clearly means: a benefit against tired eyes has not yet been proven.

The specialist societies agree. The Berufsverband der Augenärzte Deutschlands (BVA) writes in its Statement on blue light and filtering glasses: "There is also no evidence for the positive effect of blue light filtering glasses." And the AAO does not recommend a special blue light filtering glasses for computer work, as several studies have shown no improvement in symptoms.

Why your eyes get tired at the screen anyway

Burning, dry or tired eyes after a long screen day are not in your head. According to current knowledge, however, the cause is not the color of the light, but what we do at the screen.

According to the AAO people normally blink about 15 times per minute, but only 5 to 7 times at the computer. This is combined with hours of focusing on the same distance, often with poor placement, reflections, or brightness that does not match the surroundings. These are exactly the levers that can make a real difference. More on that further down.

Blue Light Hazard: Do screens harm the retina?

You may have come across the term "Blue Light Hazard" before. It describes a real physical principle: very intense blue light can damage the retina. This is shown by animal studies that the BVA also refers to. For this effect, internationally established exposure limits exist.

The decisive question is therefore not "Can blue light be harmful?", but "Do screens reach these limits?". A team led by J. B. O’Hagan from Public Health England measured this. Their study in the journal Eye (2016) examined energy-saving lamps, computers and tablets. The result: None of the sources examined even came close to the exposure limits, even with long viewing times.

The BVA reaches the same conclusion: there is no evidence of a risk of developing macular degeneration from blue light from screens. The German Social Accident Insurance also states in DGUV Information 250-008 (version April 2026): If the screen workstation is ergonomically set up and the monitor has usual luminance, blue light filtering in the lenses is not required to protect the eyes.

This is a clear statement, and it applies to every blue light filtering glasses, including ours.

How to read a data sheet: Tv, Tsb and filter category

If health claims don't hold up, the honest question is: What does the lens do physically? Only a test report answers this. The values within are standardized, primarily by the EN ISO 12312-1. You should know these four terms:

• Tv (Light transmission, 380–780 nm): How much of the total visible light passes through the lens. The higher the value, the brighter and clearer the lens appears.
• Tsb (Blue light transmission, 380–500 nm): How much blue light passes through, weighted across the entire blue range. This is the one number that honestly summarizes filtering effect.
• Filter category (0 to 4): Classifies the lens by brightness. Category 0 means according to ISO 12312-1 light transmission of over 80 %. This is a clear to very lightly tinted lens, not sunglasses.
• UV transmission (280–380 nm): How much UV radiation passes through. "UV400" means the lens lets practically nothing through up to 400 nm.
  

Why we write "around one third" and never "90 %"

The standard is surprisingly specific here. Section 5.3.5.1 of the ISO 12312-1 states: Whoever claims a lens absorbs x % blue light may have a maximum blue light transmission (Tsb) of (100,5 − x) %. Let's calculate this for BLAU II: With a Tsb of 67,30 %, you may claim a maximum of around 33 % absorption. So around one third. We are not entitled to more.

This is how the large numbers you see online come about: Our lens only lets 7,70 % through at 410 nm. Whoever cites this single measurement point can print a very high percentage on the packaging. But this is not true when calculated across the entire blue range. The curve above shows why: transmittance rises steeply from around 430 nm.

Three warning signs on product pages

• A percentage without wavelength range. "Blocks 95 %" – from which range? Without a Tsb value, the number is worthless.
• A crystal clear lens with very high blue filter. Whoever removes a lot of blue visibly changes color perception. Lenses that filter a large part of the blue range are distinctly yellow to orange (more on this in our article Where blue light filters are used today). Our lens also has a measurable, light warm tone (CIE b* 14,4). This is also part of being honest.
• Health claims instead of measured values. "Protects against headaches" or "ensures better sleep" is not supported by the study situation. A serious provider will rather show you the test report.

What really helps against tired eyes at the screen

If your eyes burn after a workday, these habits are as effective as any filtering lens, according to the AAO:

1. The 20-20-20 rule: Every 20 minutes, look for at least 20 seconds at something at least 20 feet (around 6 meters) away. Set a timer if you otherwise forget.
2. Blink consciously: Blinking rate is roughly halved at the screen. A note on the monitor ("Blink!") sounds banal, but works as a reminder.
3. Distance of about an arm's length: The AAO names around 25 inches, so about 60 cm. The gaze should be slightly downward, not straight ahead or upward.
4. Adjust brightness to the room: If the screen shines much brighter than the surroundings, your eyes have to work harder. Increase contrast if necessary.
5. Avoid reflections: The Workplace Ordinance (Annex 6) also requires that screens be set up free of disturbing reflections and glare. Windows to the side instead of behind or in front of the monitor is a good start.
6. Take dry air and dry eyes seriously: The AAO mentions moisturizing eye drops. Which ones suit you best, you should clarify at the pharmacy or ophthalmology practice.
7. Check your visual acuity: Uncorrected or outdated visual acuity is a common reason for strain at the screen. Anyone who works a lot at the screen may be entitled to an employer-funded screen workstation glasses – this is different from blue light filtering glasses.

When filtering glasses still make sense

After everything you know now: Why would anyone even wear blue light filtering glasses? Honestly, for the same reasons you choose a specific watch or jacket – because you like them.

• Style and frame: Many wear non-prescription glasses as an accessory. If so, with a lens whose values are transparent.
• Personal preference: Some people like the slightly warmer image impression that a filtering lens creates. This is taste, not health benefit.
• Transparency: You know exactly what the lens does: around one third less blue light in the 380–500 nm range, UV400, filter category 0.

What filtering glasses do not replace: breaks, a good workstation setup, and a visit to the ophthalmology practice if complaints persist. Anyone with persistent eye problems should have them clarified by a doctor – not with glasses from an online shop.

If you are interested in glasses with transparent measured values: Our BLAU II uses exactly the lens from the data sheet above (Tsb 67,30 %, Tv 89,53 %, UV400, filter category 0) in a slim frame in Transparent, Black, Gray and Olive. All models with this lens are in the Blue Light Filtering Glasses collection. We do not make any health claims here. We show what was measured.

Frequently asked questions about blue light glasses

Are blue light filtering glasses useful? Do they help against tired eyes?

According to current study data, this cannot be proven. The 2023 Cochrane Review found no clear short-term benefit compared to normal lenses across 17 studies. More well-supported are breaks following the 20-20-20 rule, conscious blinking, and good screen distance.

Does blue light from screens harm my eyes?

There is no evidence for this. Measurements from Public Health England have shown that screens and tablets remain far below the exposure limits. The DOG speaks of "no need to worry", and the BVA sees no evidence of macular risk from screens.

How much blue light does a blue light filtering glasses filter?

This depends on the lens and is stated in the test report as the Tsb value (blue light transmission from 380–500 nm). Clear lenses usually filter a smaller portion, yellow or orange lenses much more. The BLAU II lens has a Tsb of 67,30 %, so filters around one third.

What does filter category 0 mean?

According to EN ISO 12312-1, a category 0 lens lets more than 80 % of visible light through. It is thus a clear or very lightly tinted lens and not sunglasses.

Why do some providers promise 90 % blue light filtering?

Often a single measurement point at a very short wavelength is cited, for example at 400 or 410 nm. When calculated across the entire blue range, the filtering effect of clear lenses is significantly lower. The ISO 12312-1 standard links every percentage to the Tsb value.

Do I need blue light filtering glasses at work?

No. According to DGUV Information 250-008, blue light filtering is not required at ergonomically set up screen workstations. If you have poor vision at the screen, screen workstation glasses with the correct prescription are the solution. You will discuss this with your employer and ophthalmology practice.

Author: AMDOR Editorial · Status: October 2026
Note: This article does not replace ophthalmological advice. AMDOR sells blue light filtering glasses; this article therefore contains a product reference. We do not promise any health effects.

Sources

1. Singh S. et al. (2023): Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews, CD013244. pmc.ncbi.nlm.nih.gov/articles/PMC10436683
2. Berufsverband der Augenärzte Deutschlands (BVA): Stellungnahme zu Computerbildschirm, Blaulicht, Makula und Filterbrillen (Stand February 2020). augeninfo.de
3. Deutsche Ophthalmologische Gesellschaft (DOG): Entwarnung: LED-Displays sind keine Gefahr für Augen oder Schlaf. Pressemitteilung, 13.09.2021. idw-online.de/de/news775603
4. American Academy of Ophthalmology: Should You Be Worried About Blue Light? aao.org
5. American Academy of Ophthalmology: Computers, Digital Devices and Eye Strain. aao.org
6. O’Hagan J. B., Khazova M., Price L. L. A. (2016): Low-energy light bulbs, computers, tablets and the blue light hazard. Eye 30(2), 230–233. researchportal.ukhsa.gov.uk
7. ISO 12312-1:2013, Eye and face protection – Sunglasses and related eyewear, Section 5.3.5.1 and Table 1 (extract). standards.iteh.ai
8. DGUV Information 250-008: Sehhilfen an Bildschirmgeräten (Version April 2026). publikationen.dguv.de
9. Workplace Ordinance, Annex 6: Measures for designing screen workstations. gesetze-im-internet.de
10. Test report Micro-Light Optics Co., Ltd for BLAU-II lens (Tsb, Tv, UV, filter category). Values as stated in the data sheet box.