Celestial Beaver Brown FL-41 migraine glasses, square (large)
FL-41 THERAPEUTIC TINT
Rose-band notch filter

Sleepaxa Celestial Beaver Brown FL-41 Migraine Glasses

Large Square Acetate, Wide 149mm Fit
Attenuates the blue and green wavelengths most often reported as migraine and photophobia triggers.
Size54-16-145
Front width149mm
Lens height44mm
FitWide
ShapeSquare (large)
$119.00 $149.00 20% off Free shipping to the US & EU · duties and taxes included · ships worldwide from our lab
Do you need your eye power in these?
Which tint?
    *Based on spectrophotometer lab reports and reported customer experience. Individual results may vary.
    Bundle & save 15% Add a 2nd pair · day and night covered. Amber for the evening, Red for the last hours before bed — round-the-clock coverage, 15% off the pair.
    Sleepaxa Celestial Beaver Brown FL-41 Migraine Glasses – Large Square Acetate, Wide 149mm Fit
    This pairSleepaxa Celestial Beaver Brown FL-41 Migraine Glasses$119.00
    +
    The 15% discount applies automatically at checkout.
    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
    Amber lens reportView Red lens reportView

    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 paper
    Spectral 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 lensTypical blue-cut coatingDevice night mode
    Blocks the melanopsin peak near 480 nmLab-verifiedPartial, typically 10–40%No
    Covers the green band up to 550 nmRed / Circadian560 lensNoNo
    Spectrophotometer report you can openEvery batchRare—
    Granted patentsIN 587746 · IN 597482No—
    Peer-reviewed research on PubMedYesNoNo
    Covers room light, not only the screenYesYesNo
    UV protection100% UV400VariesNo
    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 widthBridgeArm length
    54-16-145149mm44mm

    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.

    IndexSuited toProfile
    1.56Up to about ±2.00 DStandard thickness
    1.61±2.00 D to ±4.00 DThinner, lighter
    1.67±4.00 D to ±6.00 DNoticeably thinner edge
    1.74Above ±6.00 DThinnest 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.

    Email our optometry team

    Choose your second pair
    The Heritage Series · FL-41

    Celestial Beaver Brown

    Deep brown acetate on the broadest front we make, for people who keep buying frames that are too small.

    Beaver brown is the darker of the two Celestial finishes, and on a frame this size the finish does practical work: a deeper tone absorbs stray light at the rim rather than reflecting it back toward the eye. The measurements are the same wide ones, a 149 mm front, a 54 mm eye, a 16 mm bridge and 44 mm of lens depth, all in Italian cellulose acetate hand-cut from a solid block and polished across more than sixty separate steps. If every frame you have tried leaves a visible gap at the outer corner, this is the width that closes it.

    Two tints, two jobs

    One wide outline, two rose depths

    FL-41 LightSteady daily filteringIndoor wear, all day. Higher overall transmittance than the dark lens with an identical rose-band notch, so the filtering character does not change, only how much light comes through. The complete spectrophotometer report is being finalized for publication here. UV400.
    FL-41 DarkHigh-glare environmentsThe curve dips through the blue and green bands, 13.8% at 450 nm and 12.6% at 520 nm, then lifts hard and reaches 100% above 670 nm. At 41.1% luminous transmittance it sits in Filter Category 2 and carries 100% UV protection.

    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 Celestial fit you?

    At 149 mm this is the widest front we publish, so it suits a broad face and will not stay put on an average one. The 54 mm eye with a narrow 16 mm bridge keeps a large square from wandering outward. The 44 mm lens depth reaches well below the pupil, which is the point of the frame, but it needs brow-to-cheekbone room. Temples measure 145 mm. Try Magnus if you want the same width in a vintage outline.

    Frame size 54-16-145
    Front width 149mm
    Lens height 44mm
    Fit Wide
    Shape Square (large)
    Collection The Heritage Series
    Material Italian cellulose acetate
    Lens options FL-41 Light or Dark · zero power or prescription
    UV protection 100% UV400, both tints
    In the box
    • Celestial Beaver Brown 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

    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.