CIRCADIAN SLEEP LENS
Long-wavelength pass filter
Sleepaxa Artisan Espresso Brown Sleep Glasses
Amber & Red Circadian Lenses
Blocks the blue and green band that suppresses melatonin, so your body starts making it on schedule.
Size51-20-145
Front width141mm
Lens height41mm
FitMedium
ShapeRectangle
$99.00
$110.00
10% 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 |
|---|---|---|
| 51-20-145 | 141mm | 41mm |
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 Heritage Series · Sleep
Artisan Espresso Brown
A warm espresso acetate rectangle that does not read as a tech product on your face.
Espresso brown is a forgiving acetate. It picks up whatever warm light is left in the room, which is exactly the light you are still allowed once the overheads go off. The Artisan runs 51-20-145 on a 141 mm front with a 41 mm lens, putting it squarely in the middle of the Heritage range and making it one of the easier frames here to hand to somebody who has never worn glasses before. Hand-cut from a solid block of Italian cellulose acetate and polished across more than sixty steps. A sensible desk frame if your problem is screen use before bed.
Two tints, two jobs
Two tints doing two separate jobs on the same frame.
Amber lensFrom dinner onwardMeasured at 0.10% transmission at 450 nm, the melanopsin peak, and 0.48% at 500 nm. By 550 nm it has opened to 40.5%, so greens are attenuated rather than deleted. Luminous transmittance 50.5%, Filter Category 1, rated for indoor and outdoor use.
Red lensThe last stretch of the eveningFrom 380 to 560 nm the measured transmission is zero. Only the long end gets through, at 5.8% at 570 nm and 49.7% at 600 nm. Luminous transmittance 14.9%, Filter Category 3, so keep this one indoors.
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 Artisan Espresso Brown is made of
| Frame material | Hand-finished Italian cellulose acetate |
|---|---|
| Frame weight | Approx. 15–18 g, lightweight |
| Hinge | Elysian hard round spring hinge |
| Frame design | Full-rim rectangle, medium 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 | Patented Circadian560 sleep lens system (patent no. 597482), designed by optometrist Suraj Dubey |
| Lens coatings | Five-layer stack: scratch-resistant hard coat, anti-reflective, tinted core, hydrophobic, oleophobic |
| Lens type | Amber or Red tint; 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 Artisan fit you?
The three numbers inside your current arm are lens width, bridge and arm length, in that order. A first number between 49 and 53 mm points at the Artisan. The 141 mm front is a true medium, so if your existing frame is 145 mm or wider and sits comfortably, size up instead. The 20 mm bridge spreads weight rather than perching it, and 41 mm of lens height keeps the rectangle proportional on an oval or square face.
| Frame size | 51-20-145 |
|---|---|
| Front width | 141 mm |
| Lens height | 41 mm |
| Fit | Medium |
| Shape | Rectangle |
| Collection | The Heritage Series |
| Material | Italian cellulose acetate |
| Lens options | Amber or Red · zero power or prescription |
| UV protection | 100% UV400, both tints |
In the box
- Artisan Espresso Brown frame in your chosen tint
- Hard case and microfiber cleaning cloth
- Spectrophotometer report reference for your lens
- One-year frame warranty, six-month lens warranty
Questions
Artisan Espresso Brown sleep glasses: quick answers
Can I get the Artisan Espresso Brown 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.
Amber or red: which tint should I pick?
Amber for the two to three hours before bed while you are still on screens or under room lights; it passes 0.10% at 450 nm and keeps colors usable. Red for the last hour and for lights-on nights; it passes nothing measurable between 380 and 560 nm.
Can I wear them outside?
The amber lens is Filter Category 1 (50.5% luminous transmittance) and is rated for indoor and outdoor use. The red lens is Filter Category 3 (14.9%) and is for indoor use only.
Will the Artisan fit me?
Artisan is a medium fit, 51-20-145 on a 141mm 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. This is the size most people take; go Wide if a medium frame leaves marks at your temples.
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.
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.