> ## 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. # What makes one reading lens better than another? > A reading lens is better when its material, coatings and transmittance are documented in a lab report, not just its printed strength. Check for a published # What makes one reading lens better than another? **By [Spektrum Glasses Editorial Team](https://kb.spektrumglasses.com/how-we-choose)** · Published 2026-08-11 · 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 A reading lens is better when its material, coatings and transmittance are documented in a lab report, not just its printed strength. Check for a published visible-light transmittance figure, wavelength-specific filtering data with the band stated, and an ANSI Z80.3 pass from an accredited lab. None of that changes a single-vision lens's one fixed focal distance. * A lab report on material, coatings and transmittance is the real spec - strength alone isn't. * ANSI Z80.3 tests light transmittance and colour, not reading-power accuracy. * A single-vision lens has one focal distance; it can't correct astigmatism or replace an eye exam. * Reading distance and screen distance differ, so one single-vision lens is a compromise between them. * Near-clear visible-light transmittance is what lets a lens read reasonably on paper and on screen. ## Specify the lens, not just the strength Reading glasses are almost always shopped on two numbers: the diopter strength and the price. Both matter, but neither says anything about the lens itself. A lens has a material, a coating, and a measured amount of light it lets through at specific wavelengths — and all three are things a manufacturer can publish in a lab report and a shopper can actually check, the same way you'd check a spec sheet on any other optical product. That is the real axis to compare lenses on, and it is one that ready-made magnifiers as a product class rarely publish anything against. A magnifier lens is typically molded to a target strength with no coating and no accompanying transmittance data. A reading lens with a published spectral report is a different kind of object to evaluate, regardless of which brand made it — the test isn't the name on the frame, it's whether the numbers exist and can be checked against an independent lab report. ## Four checks that work on any brand These four checks apply to any reading lens, ours included. If a lens can't answer them, that's useful information too. * **Anti-reflective coating on both faces** — cuts the reflections that wash out small print and screen text; a molded magnifier blank usually has none. * **Visible-light transmittance (VLT)** — the percentage of ordinary light the lens lets through. Higher means less color cast and less dimming. * **Wavelength-specific filtering, with the band always stated** — a percentage on its own ("blocks 99% of blue light") is meaningless without the nanometer range it was measured over. A lens that filters heavily at 400nm can filter far less by 450nm, so the number changes depending on where you measure it. * **An independent lab behind the numbers** — accreditation to ISO/IEC 17025 means the test was run and verified by a third party, not self-reported. Here is our own clear reading lens run through those four checks, from COLTS Laboratories report O-SPG111015 (A2LA-accredited to ISO/IEC 17025): | Check | Our clear lens | | ------------------------------------------ | --------------------------------------------------------------------- | | Visible-light transmittance | 91.6% | | Filtering at 400nm / 410nm / 420nm / 450nm | 99.99% / 95.1% / 63.0% / 33.1% | | UVA / UVB | both filtered >99.99% | | Standards pass | ANSI Z80.3 transmittance and chromaticity, pass on all samples tested | Notice the filtering percentage drops as wavelength rises — that taper is normal and any honest spec sheet will show it rather than quoting only the best number. ## What an ANSI Z80.3 pass tests, and what it doesn't Our clear lens passes ANSI Z80.3 transmittance and chromaticity testing, all samples, run by an ISO/IEC 17025-accredited laboratory. That's a real, checkable result, and it's worth asking any reading lens whether it has one. It's also narrower than the name suggests. Z80.3 covers non-prescription, non-reading-power eyewear transmittance and colour fidelity — whether the lens lets through light evenly and doesn't distort what you're looking at. It does not test whether a reading lens's magnification power is ground accurately. A lens can pass Z80.3 and still be off on its labeled diopter strength, because that's simply not what the standard measures. Treat a Z80.3 pass as a colour-and-clarity check, not as proof of magnification accuracy — and be skeptical of any lens marketed as "ANSI certified" without saying which part of ANSI it was tested against. ## The optics no lens can change No amount of coating or lab testing changes the basic optics of a single-vision reading lens, so it's worth stating plainly: a single-vision lens has one fixed focal distance. It is ground to bring one distance into focus, not a range. Reading distance and screen distance are not the same distance — a book or phone is typically held closer than a monitor sits from your eyes. A single-vision reading lens will always be a slight compromise between the two, because it can only be optimized for one. The practical guidance is to choose your strength for whichever distance you actually spend the most time at, rather than trying to split the difference. A reading lens also does not correct astigmatism, and it is not a substitute for an eye exam. Astigmatism needs a lens ground to a specific axis measurement from a refraction, which no over-the-counter single-vision reader provides. If reading is uncomfortable at a strength that should work, or text stays blurred regardless of distance, that's a signal for an eye exam, not a stronger lens off the shelf. ## Even within one catalog, "clear" isn't one number The checks above matter even inside a single product line. Our COLTS-tested clear lens filters as shown in the table above, with visible-light transmittance at 91.6%. A different clear-lens style in our own catalog, tested separately, filters roughly 52% on average across that same blue-light band, with UV filtering at 100%. Both lenses are marketed as clear. The transmittance numbers are what actually distinguish them — not the word "clear" on the listing. That's the point of running the checks rather than trusting a label: the same brand, even the same company, can sell two lenses that look identical and perform differently, and a published band-by-band report is the only way to tell them apart before you buy either one. ## Choosing a strength Non-prescription reading strengths generally run from +0.50 up to +3.00. Our own multi-strength reading style offers nine strengths across that range, and the same frame is also available with no magnification at all for people who want the lens coating and coverage without added power. Pick a strength for the distance you use most — close reading versus a monitor further away — rather than trying to average the two. A single-vision lens can't be optimized for both distances at once, so splitting the difference by sizing down doesn't resolve the compromise; it just moves it. If print stays hard to read at a strength that should be correct for your distance, that's a question for an eye care professional, not a higher diopter off the shelf. ## 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 are blue light reading glasses, and who are they for?](/answers/blue-light-reading-glasses) * [Should reading glasses have a blue light filter?](/answers/reading-glasses-with-blue-light-filter) * [Reading glasses or computer glasses - which do you need?](/answers/reading-glasses-vs-computer-glasses) * [Can one pair of reading glasses work for both books and screens?](/answers/one-pair-for-books-and-screens) * [Which reading strength (diopter) do you need?](/answers/reading-strength-diopter-guide) * [Can cheap reading glasses damage your eyes?](/answers/do-cheap-reading-glasses-damage-your-eyes) ## A PROSPEK style for this Ships from Amazon (Prime, 30-day returns). Sold by PROSPEK by Spektrum Glasses.