FL-41 THERAPEUTIC TINT
Rose-band notch filter
Sleepaxa AstroLuxe Savannah Sunburst FL-41 Migraine & Light Sensitivity Glasses
Attenuates the blue and green wavelengths most often reported as migraine and photophobia triggers.
Size50-20-145
Front width137mm
Lens height37mm
FitMedium
ShapeSquare
$99.00
$127.00
22% off
Free shipping to the US & EU · duties and taxes included · ships worldwide from our lab
Free shipping to the US & EU with duties and taxes included · delivered in 6–8 business days after dispatch.
One-year frame warranty · six-month lens warranty.
Cut, tinted and finished in the Sleepaxa optical laboratory.
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 |
|---|---|---|
| 50-20-145 | 137mm | 37mm |
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 with duties and taxes included · delivered in 6–8 business days after dispatch. 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 Heritage Series · FL-41
AstroLuxe Savannah Sunburst
A low, wide square in a graduated savannah sunburst, amber at the top fading to clear at the rim.
The AstroLuxe is the shallowest frame in the collection at 37 mm of lens height, and that low profile is the entire idea: a squared aperture sitting between the brow and the cheek without touching either. Savannah Sunburst grades the color through the acetate itself, which is only possible because the Heritage Series cuts from solid Italian cellulose acetate blocks and polishes the face across more than sixty steps. Front width is 137 mm with a 50 mm eye, a trim medium. Best suited to shorter faces, where a tall lens usually rests on the cheekbone, and to anyone who spends the day under fixed indoor lighting.
The lens
The numbers behind the rose lens
- 7.9% measured transmission at 420 nm and 13.8% at 450 nm - the blue band is attenuated across its width rather than cut
- 12.6% at 520 nm - the green band is attenuated in the same pass
- 44.2% at 570 nm rising to 100% above 670 nm - the rose band is deliberately preserved
- Luminous transmittance 41.1%, Filter Category 2
- 100% UV protection (UV400)
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.
Fit
Will the AstroLuxe Savannah Sunburst fit you?
Look inside your current arm for three numbers in the order eye, bridge, temple. AstroLuxe is 50-20-145. At 137 mm across the front it sits toward the smaller end of medium and suits faces of roughly 131 to 139 mm. The decisive figure is the 37 mm lens height, the shallowest we offer. That is ideal if your glasses normally touch your cheeks, and a poor fit if you need a progressive lens, which requires more vertical corridor than this shape provides.
| Frame size | 50-20-145 |
|---|---|
| Front width | 137 mm |
| Lens height | 37 mm |
| Fit | Medium |
| Shape | Square |
| Collection | The Heritage Series |
| Material | Italian cellulose acetate |
| Lens | FL-41 therapeutic tint · zero power or prescription |
| UV protection | 100% UV400 |
In the box
- AstroLuxe Savannah Sunburst frame with FL-41 lenses
- Hard case and microfiber cleaning cloth
- Spectrophotometer report reference for your lens
- One-year frame warranty, six-month lens warranty
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. In-stock zero-power orders are processed within 1–2 business days and most orders arrive within 6–8 business days after dispatch. 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 3–7 business days longer than a zero-power one.
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 in Surat, India, 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.