FL-41 THERAPEUTIC TINT
Rose-band notch filter
Sleepaxa Magnus Jet Black FL-41 Migraine Glasses
Extra-Wide Bold Vintage Square
Attenuates the blue and green wavelengths most often reported as migraine and photophobia triggers.
Size54-18-150
Front width147mm
Lens height40mm
FitExtra-wide
ShapeBold vintage square
$139.00
$169.00
18% off
Free shipping to the US & EU · duties and taxes included · ships worldwide from our lab
Free shipping to the US & EU, duties and taxes included · zero-power delivered in 7–11 business days (US) / 9–11 (EU); prescription 11–15 (US) / 9–14 (EU).
One-year frame warranty · six-month lens warranty.
Cut, tinted and finished in our own optical lab · available in zero power, single vision, progressive, bifocal and prism, with high-index 1.67 / 1.74 · Why Sleepaxa →
30-day returns on zero-power glasses*
*Zero-power (non-prescription) glasses only, unworn and in original packaging. Prescription lenses are made to order and cannot be returned. Returns are shipped by the customer to our warehouse; return shipping is paid by the customer. Returns policy
Spectrometer lab reports
Third-party spectrophotometer readings for this exact lens. Every batch is verified before it ships.
Evidence
What sits behind this lens.
Every claim on this page traces back to a document you can open: a spectrophotometer report, a granted patent number on the public registry, or a peer-reviewed paper indexed by the US National Library of Medicine.
Spectrometer reports
Measured, not estimated
Third-party spectrophotometer readings for this exact lens formulation, tested to EN ISO 12312-1, ANSI Z80.3 and AS/NZS 1067.1. We publish the measured number either way, not only the flattering ones.
View measured lens data
Granted · Indian Patent Office
Two granted patents
Granted Patent IN 587746 for the dual-band NeuroCalm FLX+ lens and Granted Patent IN 597482 for Circadian560 — plus four more filings. Verifiable on the government registry.
See patent register
Peer-reviewed
PubMed-indexed research
Peer-reviewed research from our founder, published in Cureus and indexed on PubMed by the US National Library of Medicine (PMID 42524168).
Read the paperSpectral behaviour
Where this lens sits on the spectrum.
Wavelength bands and what the lens does across each one. Every batch is checked on a spectrophotometer before it ships.
Comparison
Why not just any blue-light coating?
Compare the mechanism before you choose. A coating reflects a little blue; a wavelength-selective lens absorbs a defined band and publishes the measurement.
| Sleepaxa lens | Typical blue-cut coating | Device night mode | |
|---|---|---|---|
| Blocks the melanopsin peak near 480 nm | Lab-verified | Partial, typically 10–40% | No |
| Covers the green band up to 550 nm | Red / Circadian560 lens | No | No |
| Spectrophotometer report you can open | Every batch | Rare | — |
| Granted patents | IN 587746 · IN 597482 | No | — |
| Peer-reviewed research on PubMed | Yes | No | No |
| Covers room light, not only the screen | Yes | Yes | No |
| UV protection | 100% UV400 | Varies | No |
Comparison based on our published spectrophotometer reports and on typical published specifications for generic blue-light filtering coatings and device night modes. No specific competing product is named or tested here.
Before you decide
Fit, tint and prescription.
The fitWill this frame fit me?
Look on the inside of the arm of a pair you already wear. You will find three numbers, usually printed as 52–18–145. They are, in order, the lens width, the bridge width and the arm length — all in millimetres. Match those to the frame below and the fit will be close.
| Lens width | Bridge | Arm length |
|---|---|---|
| 54-18-150 | 147mm | 40mm |
If your numbers are within about 2 mm of the frame, it will sit correctly. A narrower face suits a smaller lens width; a wider face suits a longer arm.
The lensAmber or Red — which one?
Amber is the all-day lens. Luminous transmittance around 50%, Filter Category 1, safe indoors and outdoors. It removes the blue band and part of the green band while leaving enough light through to read, cook and work. Wear it from late afternoon onwards.
Red is the night lens. Zero measured transmission from 380 to 560 nm, Filter Category 3, indoor use only. This is the one to put on two to three hours before bed, when the aim is to remove the circadian signal completely rather than reduce it.
Most people who use both wear Amber in the evening and switch to Red in the last hours before sleep. That is the reason the second-pair pairing exists.
The lensPrescription and lens index
Choose Prescription Lens and we cut the tint into a lens made to your power in our own lab. After checkout you will receive an email asking for your prescription and pupillary distance — you can also reply with a photograph of the prescription.
| Index | Suited to | Profile |
|---|---|---|
| 1.56 | Up to about ±2.00 D | Standard thickness |
| 1.61 | ±2.00 D to ±4.00 D | Thinner, lighter |
| 1.67 | ±4.00 D to ±6.00 D | Noticeably thinner edge |
| 1.74 | Above ±6.00 D | Thinnest available |
Not sure which index applies to you? Send us the prescription and our optometry team will select it for you at no extra cost.
Prescription lenses are made to order for your eyes and cannot be returned or exchanged, unless we made them incorrectly — in that case we remake them free of charge.
Everything elseShipping, returns, warranty and care
Free shipping to the US & EU, duties and taxes included · zero-power delivered in 7–11 business days (US) / 9–11 (EU); prescription 11–15 (US) / 9–14 (EU). One-year frame warranty · six-month lens warranty.
30-day returns on zero-power glasses* *Zero-power (non-prescription) glasses only, unworn and in original packaging. Prescription lenses are made to order and cannot be returned. Returns are shipped by the customer to our warehouse; return shipping is paid by the customer. Read the full returns policy.
Clean the lens with the supplied microfibre cloth only. Tinted lenses are absorptive through the full thickness of the material, so surface scratches do not change the transmission curve — but they do scatter light, which is worth avoiding.
Still deciding
Ask a clinician, not a chatbot.
Tint, prescription, lens index or frame fit — our optometry team answers directly.
Choose your second pair
The Vintage Series · FL-41
Magnus Jet Black
Seventies proportions in black, sized for the faces that run out of room everywhere else.
The vintage square gives Magnus a flat brow line and squared corners, which is what lets it hold its shape on a broad face instead of vanishing. It measures 54-18-150 on a 147 mm front, firmly extra-wide, with a 40 mm lens height that sits between a shallow modern cut and a full drop. Forty millimeters is the practical sweet spot on a wide frame: deep enough that light coming from below the rim is covered, shallow enough that the lower edge never lands on the cheek when you talk.
Two tints, two jobs
Two rose tints, two thresholds
FL-41 LightEveryday indoor filteringThis is the everyday tint. It carries the same rose-band notch as FL-41 Dark at a higher transmittance, which is why most people start here. 100% UV protection (UV400). The full report for this lens is being finalized and will be published on this page.
FL-41 DarkSevere sensitivity, bright roomsRather than erase blue, this lens holds it to 7.9% at 420 nm and 13.8% at 450 nm, taking green to 12.6% at 520 nm on the same pass. The rose band is preserved on purpose, 44.2% at 570 nm rising to full transmission above 670 nm.
All figures are single-lens spectrophotometer measurements from our own laboratory reports for this lens, tested to EN ISO 12312-1, ANSI Z80.3 and AS/NZS 1067.1. Individual response varies.
Lens & Build
What the Magnus Jet Black is made of
| Frame material | Hand-finished Italian cellulose acetate |
|---|---|
| Frame weight | Approx. 15–18 g, lightweight |
| Hinge | Elysin 5-barrel screw hinge |
| Frame design | Full-rim bold vintage square, extra-wide fit |
| Lens material | CR-39 prescription-grade optical resin (index 1.50 standard; 1.56, 1.67 and 1.74 thinner indexes available for stronger prescriptions) |
| Lens technology | FL-41 rose tint for migraine, photophobia and light sensitivity, designed by optometrist Suraj Dubey |
| Lens coatings | Five-layer stack: scratch-resistant hard coat, anti-reflective, tinted core, hydrophobic, oleophobic |
| Lens type | FL-41 Light or FL-41 Dark; single vision (zero power or prescription), non-polarized; progressive available as an upgrade |
| UV protection | 100% UV400 on both tints |
| Testing | Every lens batch spectrophotometer-verified; tested to EN ISO 12312-1, ANSI Z80.3 and AS/NZS 1067.1 |
Fit
Will the Magnus fit you?
Magnus needs an extra-wide face. At 147 mm across the front it is well beyond a standard frame and will slide on an average one. The 54 mm eye pairs with an 18 mm bridge, so the nose opening is wide and the frame does not grip. At 40 mm the lens height is moderate: full coverage of the direct line of sight without cheek contact. Temples run 150 mm, longer than standard, so the arms reach further back before turning down.
| Frame size | 54-18-150 |
|---|---|
| Front width | 147mm |
| Lens height | 40mm |
| Fit | Extra-wide |
| Shape | Bold vintage square |
| Collection | The Vintage Series |
| Lens options | FL-41 Light or Dark · zero power or prescription |
| UV protection | 100% UV400, both tints |
In the box
- Magnus Jet Black frame in your chosen FL-41 tint
- Hard case and microfiber cleaning cloth
- Spectrophotometer report reference for your lens
- One-year frame warranty, six-month lens warranty
Questions
Magnus Jet Black FL-41 glasses for migraine and photophobia: quick answers
Are FL-41 glasses good for migraine and photophobia?
FL-41 is the rose tint most often studied for migraine and light sensitivity, with research going back to the early 1990s. The Magnus Jet Black lens measures 13.8% at 450 nm and 12.6% at 520 nm, attenuating the blue-green band people with migraine and photophobia most often report as uncomfortable, while keeping 41.1% luminous transmittance so rooms stay bright enough to work in. Individual experience varies.
FL-41 Light or Dark: which should I choose?
FL-41 Light for all-day indoor wear and mild light sensitivity, with minimal dimming. FL-41 Dark for strong photophobia, bright offices, fluorescent lighting and daylight glare. If you are unsure, start with Dark for your worst environment.
Do FL-41 glasses work under fluorescent lights and screens?
Fluorescent tubes, LED panels and phone or laptop screens concentrate much of their output in the short-wavelength band. FL-41 attenuates that band across its width rather than cutting a single line, which is why it is the tint most people with light sensitivity choose for offices, classrooms and long screen days.
Can I get the Magnus Jet Black FL-41 glasses in my prescription?
Yes. Choose the Prescription Lens option and send your prescription after checkout; our team confirms it within 12 to 24 hours. Lenses are CR-39 single vision by default; thinner 1.56, 1.67 or 1.74 indexes and progressive lenses are available as upgrades.
Will the Magnus fit me?
Magnus is a extra-wide fit, 54-18-150 on a 147 mm front. Read the three numbers inside the left temple of the glasses you wear now and compare: if they are close, this frame will sit the same way.
What is the return policy?
Zero-power pairs can be returned within 30 days in original condition; prescription pairs are made to order and are not returnable. Report any damaged or incorrect order within 24 to 48 hours of delivery for a replacement; support replies within 12 to 24 hours. Shipping to the US and EU is free with duties included.
Sleepaxa FL-41 eyewear is designed for visual comfort in bright and artificial light. Individual experience varies; speak with your doctor about migraine management.
Shipping. Free shipping to the United States and the European Union with import duties and taxes included — nothing to pay on delivery. Rest of the world: shipping is calculated at checkout and any local duties or taxes may be payable by the recipient. Zero-power orders are processed within 1–3 business days and arrive in 7–11 business days in the United States, 9–11 in Europe and 9–14 elsewhere. Every order ships from our own optical laboratory.
Prescription orders. If you selected a prescription lens, our optometry team emails you after checkout to confirm your power and pupillary distance. Lenses are not cut until that confirmation, so a prescription order takes 4–6 business days to prepare and arrives in 11–15 business days in the United States, 9–14 in Europe and 13–18 elsewhere.
Returns. Zero-power (non-prescription) glasses may be returned within 30 days of delivery, unworn and in the original case with the cloth and packaging. Prescription and custom lenses are made to order and cannot be returned or exchanged unless we made them incorrectly. Returns are shipped by the customer to our warehouse, and return shipping is paid by the customer. See our Returns policy for the full process.
Warranty. One-year frame warranty and a six-month lens warranty covering manufacturing defects. Accidental damage and normal wear are not covered.
Lens care. Clean only with the supplied microfibre cloth. Our tints are absorptive through the full thickness of the lens material, so surface scratches do not change the transmission curve — but they do scatter light, which is worth avoiding. Do not use paper tissue, alcohol wipes or household cleaners.
Standards. Every lens carries 100% UV protection (UV400) and is tested against EN ISO 12312-1, ANSI Z80.3 and AS/NZS 1067.1. Spectrophotometer reports for each lens family are published on our research page.
Questions. Write to connect@sleepaxa.com and our optometry team answers directly.