> ## Documentation Index > Fetch the complete documentation index at: https://kb.spektrumglasses.com/llms.txt > Use this file to discover all available pages before exploring further. # Glare or blue light: which one is tiring your eyes? > Most digital eye strain comes from behavior, not light: reduced blinking, sustained near-focus, screen glare, and poor posture drive it, not any particular # Glare or blue light: which one is tiring your eyes? **By [Spektrum Glasses Editorial Team](https://kb.spektrumglasses.com/how-we-choose)** · Published 2026-08-13 · Updated 2026-08-15 · Facts re-checked 2026-08-15 *How this page is written and checked: [our editorial method](https://kb.spektrumglasses.com/how-we-choose) · [how we verify claims](https://kb.spektrumglasses.com/how-we-verify)* ## Short answer Most digital eye strain comes from behavior, not light: reduced blinking, sustained near-focus, screen glare, and poor posture drive it, not any particular wavelength. Current peer-reviewed research finds blue-light-filtering lenses have little to no measurable effect on eye comfort measures tested so far. Blinking more, taking breaks, fixing glare, and adjusting posture help more than any lens color. * Reduced blink rate, sustained near focus, and posture drive most reported digital eye strain, not blue light. * Peer-reviewed research finds blue-light-filtering lenses have minimal or no significant effect on contrast sensitivity, task performance, or sleep measures in RCTs. * Screen glare and overhead lighting are separate problems from blue light and respond to monitor position and lighting changes, not lens color. * Our clear lens is 91.6% visible-light transmissive and filters specific wavelength bands, per accredited lab testing; it is a small addition, not a complete solution. * Simple habits - blinking, breaks, screen distance, room lighting - address the causes with the most evidence behind them. ## What causes digital eye strain "Digital eye strain" is usually a bundle of separate mechanical and environmental factors, not one cause. People blink less often while concentrating on a screen, which dries out and irritates the eye's surface. Sustained near-focus for hours keeps the eye's focusing muscles engaged without a break. Poor screen positioning - too close, too high, or too low - adds neck strain that gets lumped into the same complaint. Glare and reflections force squinting and constant readjustment. None of this depends on the color of the light coming off the screen. Because the causes are mostly behavioral, the fixes with the most direct evidence are behavioral too: blink deliberately and fully, look away from the screen on a regular rhythm, position the monitor at arm's length and slightly below eye level, and keep screen brightness close to the room's ambient light so the eye isn't constantly readjusting. These cost nothing and act on the actual mechanism. A lens acts on only one input - the light reaching the eye - and not on blinking, focusing effort, or posture at all. ## Glare is a real, separate problem Glare comes from light reflecting off a glossy screen or bouncing off overhead lights, a window, or a bright wall behind the monitor into the line of sight. It forces the eyes to fight two competing light sources at once, which is a common trigger for squinting. Practical fixes: a matte screen or matte screen protector, positioning the monitor perpendicular to windows rather than facing or backing onto them, dimming or diffusing harsh overhead lighting, and matching screen brightness to the room rather than working in a dark room with a bright screen (or the reverse). Glare shows up off the screen too, and it's worth being precise about what the data does and doesn't say there. A 2026 national AAA survey found that about six in ten drivers report struggling with headlight glare at night - genuine, common discomfort. Separately, an IIHS analysis of roughly 24 million crashes across 11 US states from 2015 through 2023 found glare was a contributing factor in only 1 to 2 of every 1,000 nighttime crashes, with no increase over that period even as headlights got brighter; headlight glare performance in new vehicles has in fact improved sharply, with only 3% of model-year-2025 systems rated poor for glare versus 21% of model-year-2017 systems. The discomfort drivers report is real. A crash-safety claim built on top of that discomfort is not supported by the data, which is one reason this catalog doesn't make crash-safety claims for any lens. ## What the blue light research actually shows Blue light gets more blame than the current evidence supports. A meta-analysis of three randomized controlled crossover trials (n=49, measured by actigraphy), published in Frontiers in Neurology in November 2025, found no significant difference between blue-light-filtering and standard lenses in sleep onset latency, total sleep time, sleep efficiency, or wake time after sleep onset. The authors describe the RCT evidence as not supporting a significant effect, while allowing that a small effect may still exist below what current trials can detect. A January 2026 review in Therapeutic Advances in Ophthalmology reached a similar conclusion for daytime use: blue-light-filtering spectacle lenses showed minimal or no measurable difference from standard lenses on contrast sensitivity, color discrimination, or task performance, and it describes the outcomes most relevant to a tired workday - eye comfort and circadian timing - as still debated in the literature. Where the evidence is stronger is the optics, not the person. A 2017 study in PLOS ONE found that commercially available blue-light-filtering lenses reduced the calculated blue-light hazard - a weighted exposure measurement across the blue portion of the visible spectrum - by roughly 10 to 24%, depending on the lens tested. That's a real, measurable optical property. Whether cutting that exposure changes how tired a person's eyes feel by the end of a workday has not been established by the controlled research available so far. ## What our lens data does and doesn't show Our standard clear lens was measured by COLTS Laboratories (report O-SPG111015, A2LA-accredited to ISO/IEC 17025, spectral transmittance tested per ANSI Z80.3). It filters 99.99% of light at 400 nm, 95.1% at 410 nm, 63.0% at 420 nm, and 33.1% at 450 nm, while passing 91.6% of visible light overall - both UVA and UVB are filtered above 99.99%. That 91.6% figure is what keeps the lens looking and reading like a clear lens rather than a tinted one; it is a transmittance measurement, not a claim about eye comfort. The lens passed ANSI Z80.3 transmittance and chromaticity testing, but that standard covers light transmittance and color only - it says nothing about focusing effort, glare from reflections, or (for styles with reading magnification) the accuracy of the reading power. A coating that filters part of the blue band is a real, measured optical property. It is one small input into a much larger picture that's mostly about behavior and environment, as covered above. More filtering also isn't automatically better for daytime screen work. Our yellow evening lens filters about 98% of the 400-500 nm band at roughly 65% visible transmission - a heavier tint built for evening use, not for a bright office, because cutting more visible light makes a screen harder to read in daylight, not easier. ## Habits that address the actual causes Independent of any lens, these act directly on the mechanisms described above: * Blink on purpose. Concentration on a screen suppresses the blink reflex; consciously blinking fully and often keeps the eye's surface from drying out. * Look away on a rhythm. Shifting focus to something farther away regularly lets the eye's focusing muscles rest instead of holding one near distance for hours. * Fix the glare, not the light. Angle the screen away from windows and overhead fixtures, use a matte screen or protector, and match brightness to the room instead of glowing in a dark space. * Check posture and distance. A screen at arm's length and slightly below eye level cuts the squinting and neck strain that often get folded into the same complaint. * Treat a dry room as part of the problem. Low humidity and forced-air heating or cooling dry out the eye surface faster than any particular wavelength of light does. A lens that filters part of the blue spectrum, like ours, is a small, measured addition on top of these habits - not a substitute for any of them. ## Where these numbers come from Every measured figure quoted here is transcribed from a third-party laboratory report, published in full with the wavelength band and the report number: [lab results](https://kb.spektrumglasses.com/lab-results). Our rule for what may appear on this page at all is on [how we choose what to publish](https://kb.spektrumglasses.com/how-we-choose). ## Related questions * [What is digital eye strain?](/answers/what-is-digital-eye-strain) * [What actually causes eye strain at the computer?](/answers/what-causes-eye-strain-at-the-computer) * [Do blue light glasses help with eye strain?](/answers/do-blue-light-glasses-help-eye-strain) * [What is the 20-20-20 rule and does it work?](/answers/the-20-20-20-rule) * [What are the symptoms of computer vision syndrome?](/answers/symptoms-of-computer-vision-syndrome) * [Why do my eyes burn after a long day at the screen?](/answers/why-do-my-eyes-burn-after-screen-time)