> ## 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. # How much screen time is reasonable for kids? > There is no single 'reasonable' number we can responsibly give you; total daily hours is a pediatric guidance question, not an eyewear one. What matters mo # How much screen time is reasonable for kids? **By [Spektrum Glasses Editorial Team](https://kb.spektrumglasses.com/how-we-choose)** · Published 2026-08-15 · Updated 2026-09-11 · Facts re-checked 2026-09-11 *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 There is no single 'reasonable' number we can responsibly give you; total daily hours is a pediatric guidance question, not an eyewear one. What matters more is timing, especially screens close to bedtime, plus regular breaks. A yellow evening lens may modestly cut blue-light exposure at night, but it does not replace a bedtime routine or a screen-time limit. * No universal 'safe' screen-time number exists; that call belongs to pediatric guidance, not an eyewear brand. * Timing likely matters more than total hours: screens close to bedtime are the bigger concern versus daytime use. * Our yellow evening lens filters 98% of the 400-500 nm band and 98.3% at the 460-480 nm melatonin band. * Peer-reviewed RCT evidence on blue-light lenses and sleep outcomes is small, mixed, and largely done in adults. * Our clear lens (91.6% visible transmission) suits daytime schoolwork but filters little blue light above 420 nm. ## This is a parenting and pediatric question first How many hours a day is reasonable for a child to spend on a screen depends on the child's age, the content, homework requirements, and family routines. That is a pediatric and public-health question, and it is outside what an eyewear company can responsibly answer with a specific number. We are not going to invent one. What we can speak to, because we measure it, is what a lens does and does not do to the light reaching a child's eyes during screen use. That is a narrower and much more answerable question, and it is where the rest of this page stays. ## What is actually likely to matter during screen use Independent of any lens, the factors most often discussed in relation to kids and screens are behavioral: how close to bedtime the screen is used, how long a single session runs without a break, viewing distance and posture, and room lighting. None of these are things a pair of glasses controls. A lens cannot enforce a bedtime, shorten a session, or fix poor posture. If a child is struggling with sleep timing after evening screen use, or with fatigue after long sessions, the highest-leverage changes are schedule and habit changes, not an optical filter. We think it is more useful to say that plainly than to suggest a lens is a substitute for it. ## What the research on blue-light lenses actually shows The strongest available evidence here comes from adult studies, not child-specific trials, and it is mixed. A 2025 meta-analysis of three randomized controlled crossover trials (n=49, actigraphy-measured) found sleep onset latency, total sleep time, sleep efficiency, and wake-after-sleep-onset were all statistically non-significant between blue-blocking and control lenses; the authors describe any effect as small and say current RCT evidence does not support a significant effect on those measures. A separate 2026 review in Therapeutic Advances in Ophthalmology found blue-light-filtering spectacle lenses showed minimal or no significant difference from standard lenses on contrast sensitivity, colour discrimination, or task performance, and describes the evidence for circadian and sleep-related outcomes as debated. On the optical side, a 2017 PLOS ONE study found commercially available blue-light-filtering lenses reduced the calculated blue-light hazard by roughly 10-24% versus standard lenses. That is a measurable optical effect, not a proven behavioral or sleep outcome. We think it is important to keep those two claims separate, because a lot of marketing in this category blends them. ## Where our yellow evening lens may fit Our yellow evening lens, tested by COLTS Laboratories (report O-SPG111015, A2LA-accredited to ISO/IEC 17025, spectral transmittance per ANSI Z80.3), filters 98% of the 400-500 nm blue band, 99.9% of high-energy visible light, and 98.3% at the 460-480 nm band most associated with melatonin suppression in the research literature, at roughly 65% visible-light transmission. That is a real, measured reduction in the blue light reaching the eye during evening use. Given what the RCT evidence above actually shows, we describe this honestly: it may help as one part of a wind-down routine for a child using a screen in the hour or two before bed, but the peer-reviewed evidence for a measurable sleep benefit is thin and contested. It is not a stand-in for ending screen use before bedtime. If a family wants to try it, it makes more sense as a companion to an earlier cutoff than as a replacement for one. ## Where our clear lens fits, and where it does not For daytime schoolwork and general screen use, our clear lens (COLTS report O-SPG111015) transmits 91.6% of visible light, so it looks and reads essentially like an uncoated lens, with UVA and UVB both filtered above 99.99%. It filters 99.99% at 400 nm and 95.1% at 410 nm, but that falls off fast: only 63.0% at 420 nm and 33.1% at 450 nm. In practice, that means it is a near-clear, comfortable option a child can wear all day without a visible tint, but it does very little to the broader 420-500 nm blue band compared with the yellow evening lens. Daytime blue-light exposure is generally treated as less of a concern in the research above than evening exposure close to bedtime, so this tradeoff — comfort and clarity over heavy filtering — fits how the lens is meant to be used: at school or on homework, not as an evening sleep aid. ## The honest bottom line If a family is trying to figure out how much screen time is right for a child, that answer should come from a pediatrician or established public-health guidance, not from us. If the concern is specifically about evening screens and bedtime, the biggest lever is timing and routine; a yellow lens with a measured reduction across the 400-500 nm band may be a reasonable addition to that routine, but the published RCT evidence does not support treating it as a solution on its own. ## 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 * [Are blue light glasses worth it for gaming?](/answers/blue-light-glasses-for-gaming) * [Gaming glasses vs computer glasses: is there a difference?](/answers/gaming-glasses-vs-computer-glasses) * [Are blue light glasses worth it for programmers?](/answers/blue-light-glasses-for-programmers) * [Are blue light glasses worth it for students?](/answers/blue-light-glasses-for-students) * [Should kids wear blue light glasses?](/answers/blue-light-glasses-for-kids) * [Can designers wear blue light glasses without losing color accuracy?](/answers/blue-light-glasses-for-designers) ## A PROSPEK style for this Ships from Amazon (Prime, 30-day returns). Sold by PROSPEK by Spektrum Glasses.