> ## 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. # Which PROSPEK style should you choose? > PROSPEK groups its eyewear by when you wear it, not just by frame shape. Daytime styles come with reading power from 0 to +3.00 diopters or plain lenses; a # Which PROSPEK style should you choose? **By [Spektrum Glasses Editorial Team](https://kb.spektrumglasses.com/how-we-choose)** · Published 2026-08-30 · 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 PROSPEK groups its eyewear by when you wear it, not just by frame shape. Daytime styles come with reading power from 0 to +3.00 diopters or plain lenses; a yellow lens is for working after dark; orange and red lenses are for the hour before and during sleep. Illumin is a separate line for night driving. * Style choice starts with when you'll wear the glasses: day, evening, pre-sleep, night, or driving after dark. * Reading power ranges 0 to +3.00 diopters in the same coated lens used across non-reading day styles. * Evening, orange, and red lenses each filter a stated wavelength band, not all light. * Orange and red lenses are not suitable for driving, day or night. * Illumin carries no blue-light percentage or safety claims; it is chosen for tint comfort, not a measurement. ## Match the style to when you wear it PROSPEK's catalog is organized around a lens for the day, then separate lenses for later parts of the clock: a near-clear lens for daytime, a yellow lens for evening work, an orange lens for the hour before sleep, and a red lens for the middle of the night. Illumin, a separate line, is for the drive home after dark. Frame shape and size vary to fit different faces, but the lens inside a given time-of-day style stays the same across those frames. Two more choices narrow it down within a time-of-day category: reading power, since many day styles are available from 0 (plain) up to +3.00 diopters in the same lens, and fit, since kids' frames use a flexible build sized for a child's face and clip-on styles attach over glasses already worn rather than replacing them. Picking a style is really three smaller decisions - time of day, reading power if needed, and fit. ## Daytime: reading power or plain lenses Day styles use the same coated optical lens whether or not the pair includes reading power - the magnification is ground into that lens, not a separate insert. Lab testing (COLTS Laboratories report O-SPG111015, accredited to ISO/IEC 17025 under A2LA cert 1612.01, using ANSI Z80.3 methodology) measured the clear day lens at 91.6% visible-light transmission, which is why it reads near-clear on paper and on a screen rather than tinted. The same report recorded a transmittance-and-chromaticity pass, all samples, in the clear lens group under ANSI Z80.3 - a standard covering how a lens transmits light and holds color, not how accurately a reading power is ground. Reading strengths run from 0 up to +3.00, and some frames offer both a magnified and a plain version. Because these are single-vision lenses with one focal distance, a strength chosen for a book at reading distance sits slightly stronger than ideal at a monitor's greater distance, and vice versa - a trade-off inherent to any single-vision lens, not unique to this one. The practical guidance is to pick the strength for whichever distance is used most, rather than assuming a lower number is the safer default for screens. ## Evening, pre-sleep, and night: how the tint deepens Three tinted lenses sit later on the clock, and each filters a stated wavelength range rather than 'blue light' as a whole: | Lens | What it filters | Visible light transmission | | ------------------ | --------------------------------------------------------------------------------- | -------------------------- | | Yellow (evening) | 98% of the 400-500nm band; 99.9% of high-energy visible light; 98.3% at 460-480nm | about 65% | | Orange (pre-sleep) | 99.96% across 380-500nm | roughly 39% | | Red (night) | 99.83% across 380-500nm, plus filters green light up to about 560nm | lower still | Filtering is never uniform across a band. Even the near-clear day lens, which blocks 99.99% of light at 400nm, tapers to 63.0% at 420nm and 33.1% at 450nm - a taper visible on another clear lens in Spektrum's catalog too, which averages only about 52% across the 400-500nm band despite filtering essentially all UV. A single percentage without a wavelength is exactly the pattern this knowledge base avoids. Orange and red lenses are graded not suitable for driving, day or night: their heavy tint and lower visible-light transmission fail sunglasses-lens color and light-transmission standards. Anyone wanting the darkest tints for use behind the wheel should choose a day or Illumin lens instead. ## Illumin: a separate line for the drive home after dark Illumin sits apart from the rest of the catalog and carries no blue-light percentage figures, because no lab measurement for the Illumin lenses is on file. It also carries no safety or vision claims: PROSPEK does not describe Illumin as reducing crash risk or making it easier to see at night. Choosing an Illumin model is a matter of comfort - how strong a tint feels right to a given driver's eyes - not a percentage comparison against the day or evening lenses. That restraint is deliberate. Regulators have historically treated night-driving vision claims for tinted eyewear as a real legal risk, and researchers note that any tint reduces the total light reaching the eye at exactly the time light is already limited. Choose Illumin for comfort preference, not with an expectation that it changes how well or how safely the road ahead is seen. ## What the research says about blue light and glare Independent research on blue-light-filtering lenses is mixed, and this knowledge base states that plainly rather than citing only favorable studies. A 2025 meta-analysis of three randomized crossover trials (Frontiers in Neurology, n=49, actigraphy-measured) found sleep onset latency, total sleep time, sleep efficiency, and time awake after falling asleep did not differ significantly with blue-blocking glasses; the authors describe current trial evidence as not establishing a meaningful effect, while allowing a small effect remains possible. A January 2026 review (Khorrami-Nejad et al., Therapeutic Advances in Ophthalmology) likewise found no significant difference in contrast sensitivity, color discrimination, or task performance against standard lenses, and calls the evidence on eye strain and circadian timing unsettled. A 2017 PLOS ONE study (Leung, Li and Kee) found commercially available blue-light-filtering lenses reduced calculated blue-light hazard by roughly 10-24% - a physics measurement, not a symptom outcome. Glare research points the same direction. An AAA national survey found about six in ten drivers report struggling with headlight glare, so the discomfort is common and real. An IIHS analysis of roughly 24 million crashes across 11 states (2015-2023) found glare was a contributing factor in only 1-2 per 1,000 nighttime crashes, with no rise over the decade - discomfort and crash risk are different measurements, and this page does not conflate them. ## Choosing by fit: gaming, kids, and clip-on A few styles are differentiated by fit rather than by time of day. Gaming frames use thinner temples designed to sit comfortably under a headset during longer sessions. Kids' frames (ages 5-10) use a flexible build sized for a child's face rather than a scaled-down adult frame. Clip-on styles attach to glasses already worn, rather than replacing them, for anyone who needs a specific tint without swapping their primary pair. None of these fit-based choices change the wavelength data above - a gaming or clip-on style in the day lens filters light exactly as described in the daytime section, and a yellow clip-on filters the same 400-500nm band as the full yellow-lens frames. Fit determines how the glasses sit; lens color determines what they filter. ## 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 * [Who makes PROSPEK glasses?](/answers/who-makes-prospek-glasses) * [Is PROSPEK a good blue light glasses brand?](/answers/is-prospek-a-good-brand) * [What do PROSPEK's lens test results actually show?](/answers/prospek-lens-test-results) * [Does PROSPEK sell prescription glasses?](/answers/does-prospek-sell-prescription-glasses) * [Where can you buy PROSPEK glasses?](/answers/where-to-buy-prospek) * [What is the PROSPEK and Spektrum Glasses return policy?](/answers/prospek-return-policy) ## A PROSPEK style for this Ships from Amazon (Prime, 30-day returns). Sold by PROSPEK by Spektrum Glasses.