How to choose well anti-blue light glasses, fit-overs/flip-ups, or screen protector? Many of you ask this excellent question. Yet, the only way to know whether any given blue blocker will really work for you has been to try it … which is often not easy. Now you can use GLARminŸ Tester to guide you through your blue light filter shopping process.

Blue light filter Tester wraparound fit nature


GLARminŸ Tester is very simple to use (also over prescription glasses):

purchase GLARminŸ Tester via PayPal ($20US worldwide shipping included)
– wear it using different blue light filters (it comes with 8 of them)
– when you find the one that works best for you, consult this table to identify and purchase a similar product (glasses, fit-overs, flip-ups, screen protectors).

But, if you want to know everything about GLARminŸ Tester, read on.



– The current state of research and experience on blue light filter effects
– How to find a suitable blue blocker, the old way
– GLARminŸ Tester – description of the product
– Recommended filter testing approach
– TABLE: Finding a best matching blue blocker to buy
– Care & use instructions

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User from the USA:

I just received the testers. Within 20 minutes, it is very clear that the “0”s are the best for pain blocking, but my visual acuity is degraded, as expected.

I’d gone to some great neurologists and optometrists in California, and paid a lot of money to try to solve my light sensitivity problem, with no success. I am an engineer, so I did a bit internet research, I get your test kit, from Slovenia no less, and I get immediate relief. I should get a refund from the doctors and send it to you!

Thank you very much!

It is the wild, wild west … of blue light!

Vendors often try to convince us that their blue light filter is the answer to blue light induced problems. Many use the bad blue light vs. good blue light argument, which is not rooted in research nor experience, but rather in their desire to sell more to uninformed buyers by oversimplifying.

Everyone willing to read more than one report (or sales ad) on the effects of blue light, quickly realizes, that there is absolutely no agreement on what specific frequency or frequencies of light to attenuate, nor how far to attenuate said frequencies. Further, every manufacturer seems to have their own particular interpretation of “blue light”, and how they choose to “manage” it varies wildly. This statement is as true today as it was in 2014 when it was posted by an optician on a forum for eyecare professionals.

Yet, don’t be surprised by this ambiguity. Both science and experience confirm that it is impossible to know apriori which blue light filter (if any) will work for a specific person. We still know too little to make predictions say top vision scientists researching the complex non-visual (biological and behavioral) responses to (blue) light [Measuring and using light in the melanopsin age. (2014)]. Therefore, the experience of many makes sense: you need to try a blue blocker to know whether its spectral transmission characteristics will work for you – see here, here, and here).

Note also, that the way our brain processes light inputs may be quite unique. Paradoxically, some people experience improved visual comfort with filters that transmit blue light and block other wavelengths instead! Therefore, if you don’t find relief with blue light filters, you may still hope to find your solution elsewhere.

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How can you know which blue light filter will work for you?

Even when you’ve invested time in studying how blue light affects people, the task of choosing the right blue light filter is overwhelming. There are so many different blue blockers available in the market, many different problems associated with blue light, more or less aggressive lighting setups, and many different responses of different people to similar light stimuli. It is, therefore reasonable to expect that when choosing a blue light filter (without testing it), one is likely to make a mistake.

Hence, this important advice: Make sure you check vendor’s return policy before ordering a blue blocker.

Until now you could test blue light filters in two ways:

  • buy it, see how it affects you, keep or return
  • find an eye doctor’s office, either an ophthalmologist or an optometrist, or a local blindness/low vision agency that will let you try a range of blue light filters (different lenses of varying tints, contrast, color balance, and transmission). Note that the first impression may not be indicative of the final effect of using a blue light filter, so plan on trying each filter at least for 10-15 minutes.

Both options have important downsides: The first may be a long and stressful process, particularly when you need a solution badly and fast. As for the second alternative, not everyone lives conveniently close to agents that provide this service.

Another downside of this process is that many of the filters you might try don’t come equipped with spectral transmittance data. This means that you cannot know what spectral transmission profile works for you. Subsequently, the next time you want to buy a blue light filter, you either have to order the exact same filter, from the same manufacturer, or go through the above-described testing process again.

The purpose of GLARminŸ Tester is to solve these inconveniences. It allows you to find out before buying glasses, fit-overs, clip-ons, or a screen protector if its spectral transmission properties are adequate for your eyes or not. Best of all, you’ll know it no matter what your blue light associated condition: visual discomfort, computer eye strain, dry eyes, headaches, eye strain from office lighting, insomnia, migraine, benign essential blepharospasm (BEB), traumatic brain injury (TBI), photophobia – light sensitivity, discomfort glare, Age-related Macular Degeneration (AMD), low visual acuity, distance vision, contrast sensitivity, etc… [Diagnosis, Pathophysiology and Treatment of Photophobia (2016), The Visual Effects of Intraocular Colored Filters (2012)].

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GLARminŸ Tester

GLARminŸ Tester is eyewear with a set of interchangeable blue light filters with different spectral transmission properties. Another important component of the Tester is a tabular overview of most commercially available blue light filters with known spectral transmission. The table should help you match a GLARminŸ Tester Filter with similar commercial blue blockers (or compare/match the blue blocker you are currently using with other, similar blue light filters).

Blue light filter Tester S


GLARminŸ Tester frame was designed to block out most of the unwanted, unfiltered light, and fit small, large heads and even over prescription glasses.

Blue light filter tester-over prescription glasses LGLARminŸ fits over prescription glasses (temple length may be adjusted).


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User from the USA:

An amazing selection of filters!


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The 8 blue light Filters

GLARminŸ Tester takes advantage of the fact that two blue light filters with comparable spectral transmission properties produce a similar response to equivalent lighting conditions.


Blue light filter tester-how to interpret spectrogramsSpectral transmission curve describes what proportion of each light wavelength a filter lets through (% Transmission) and what proportion it blocks (100%-% Transmission).

GLARminŸ Tester Filters were selected based on the properties of human vision and spectral power distribution of common light sources that frequently cause problems (click hyperlinked text below to view spectrograms):

– spectral sensitivities of our photoreceptors for sharp vision: M (or Green) and L (or Red) cones – peak sensitivities near 530nm and 560nm respectively

– spectral sensitivity of our photoreceptors responsible for sleep regulation (ipRGCs) – high sensitivity 480nm +/-50nm

– blue blocking properties of our natural blue light filter, macular pigmentminimum transmittance around 460nm; This is very important because many of us have a deficient Macular Pigment Optical Density (MPOD)

LED spectral power distributionhigh peak in the blue region – near 450nm (most modern computer screens are LED backlit)

fluorescent light spectral power distribution – local peaks of blue light near 405nm, 435nm, and 490nm

Moreover, three filters were selected to resemble the three popular brands of blue blockers: Gunnar computer glasses and fluorescent light protection & migraine relief glasses with the FL-41 tint from Axon Optics and TheraSpecs.

For more detailed info and references to scientific reports see this guide on choosing a blue light filter, and this article on indoor lighting and eye strain.


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Spectral characteristics of the Filters


Blue light filter Tester 8 Filters photo L

GLARminŸ Tester Filters are ordered from blocking more to less blue light (to view spectral transmission graphs click below):

Filter 0: filters/blocks most light up to 580nm: longer wavelength light should not affect sleep hormone production.

Filter 1: blocks near 100% of light up to about 525nm: this cutoff is comfortably above what is usually considered blue light (400-500nm). It is also comfortably above our eye’s peak sensitivity  for sleep hormone regulation (near 480nm). In many people, such a filter blocks enough blue light to improve their sleep.

Filter 2: cutoff at 490nm which is just above peak sensitivity of sleep regulation and comfortably above peak absorption of macular pigment and high blue light emissions of digital screens and energy saving (LED, fluorescent) lamps. Filter 2 features high transmittance at peak sensitivity wavelengths for sharp vision (530, 560nm).

Filter 3: cutoff at 460nm – blocks all light up to the peak absorption wavelength of macular pigment (460nm); it also blocks all light near the power peak of LED lamps and digital screens (450nm). Filter 3 lets through plenty of light for sharp vision photoreceptors (peaking at 530, 560nm).

Filter 4: a best match for spectral transmission characteristics of TheraSpecs migraine relief indoors FL-41 lens.

Filter 5: mimics reasonably the spectral transmission curve of Gunnar blue blocking computer glasses with Amber tint.

Filter 6: imitates reasonably spectral transmission properties of Axon Optics migraine relief indoors FL-41 lens.

Filter 7: cutoff at 400nm; above 80% transmission by 440nm. It is a clear filter that does not distort color. Remember that computer screens emit lots of blue light in the 440-460nm range where this filter blocks hardly any. In spectral transmittance profile, Filter 7 is similar to those blue blockers that don’t distort color (see table).

Note that spectral transmission properties of GLARminŸ Tester Filters are similar (but not identical) to the eyewear and screen protectors available in the market. The matches are as close as specified in the table – in most cases close enough to help you choose the filter that will produce the same response in assisting you with your problem. At the very least, the tester should point you towards the most suitable product for your eyes.

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User from the UK:

To date, I have conducted some small tests with lens 1 and 2. I find both helpful but perhaps too strong for my needs, especially when combined with the IRIS software on my computer. So, I will continue with my experimentation and work through the lens.

Interestingly, I suspect I will need more than one pair of glasses with different blue filtering lens for different activities.

[A few days later:]
I am now testing filter number 3 and getting on well with this filter. I will continue with the experimentation and let you know which filters work best for me in different scenarios.

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How to test your blue light sensitivity: The recommended approach


Blue light filter tester-Changing filters LChange the trial Filters easily: take one out of the frame and insert another through the opening on the upper side of the frame.

You can test different GLARminŸ Tester Filters randomly, however by following the below-described method, you are more likely to find your favorite Filter faster.

Your first task is to figure out if blue light is, indeed, causing your problem. Next, you may want to find out what is the minimum amount of blue light you need to block to achieve the desired improvement. Once you know which GLARminŸ Tester Filter works for you, you can look up the corresponding, commercially available, blue light filters and order the one you like best.

Start with Filter 1. GLARminŸ Tester comes with Filter 1 inserted in the frame. Since Filter 1 blocks all blue light, you should feel an improvement if your condition is indeed caused by blue light. (Depending on your condition the improvement may or may not be immediate). If, however, Filter 1 feels helpful, but too dark, your eyes may be more comfortable with a weaker Filter (higher number).

Insomnia. For most Filter 1 should be effective against blue light induced insomnia. However, if after several days of wearing Filter 1, for 2-3 hours before bedtime, you don’t notice any improvement in your sleep pattern, you might consider trying Filter 0, which blocks all the wavelengths that affect sleep hormone production.

Note that fixing sleeping disorders may be a slow process, so be patient. Also, blue light is not the only cause of insomnia, so make sure you’ve also eliminated other possible causes.

If Filter 1 helped you improve your condition you can go ahead and purchase one of the products with a similar spectral transmission (see table).

However, to absorb all blue light, Filter 1 has a strong orange tint to it, and because it blocks all blue light it distorts color considerably.

Although color distortion is to be expected – you can’t block blue light and see it too – you might want to find out if you can decrease the proportion of blue light filtered without reducing the positive response produced by Filter 1. In practice, that means that the filter won’t distort color as much and its tint will be more discreet.

Reducing the proportion of blue light blocked:

Replace the last Filter tested with the next (one number higher) Filter. Use it for a few days to see how you feel:

  • If it feels as good or better than the previous Filter, repeat the above instruction.
  • If it feels worse you should purchase a blue light filter (glasses, fit-overs, screen protector) with spectral properties similar to the previous Filter.

Note also that to achieve the same visual comfort, different filters may be required depending on the harshness (level of blue light content) of light: the more blue light content, the stronger blue blocker.

Filter 7. If by following the above procedure you get to Filter 7 and feel comfortable with it, you may not need blue blockers. The next level down in the blue blocking capacity would be a normal, non-blue blocking, clear lens/filter).

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User from Czech Republic:

I have been testing the filters you sent me and I must say I notice a difference. Especially with Filters 2 and 3. I still feel some discomfort, but it doesn’t develop into a migraine or stinging pain behind my eyes as it happens without the Tester. The world is also very nice in the cast of yellow. 🙂

I am surprised as this means the problem is definitely related to blue-light.

I will keep testing the different Filters and see how it goes. Filter 7, however, seems too weak for me so far.

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From a GLARminŸ Tester Filter to a similar, commercially available, blue blocker

The table below positions each of the eight GLARminŸ Tester Filters in the context of similar commercially available filters for which spectral transmission data is known.

The filters are ordered by how much blue light they block/filter. At the top there are filters that block more blue light, further down the list less and less blue light is blocked. (In the ordering of the filters, the blue blocking rate at 450nm is weighted most because it is the wavelength of peak emission of digital screens and LED bulbs. It is also close to the peak absorption of macular pigment).

Tester Filters are bolded to be found more easily. The more distant a commercial filter from a Tester Filter, the more different its spectral properties. Those above a GLARminŸ Tester Filter block more blue light (as specified), those below it block less.

For ease of comparison, blue blocking rates at six different wavelengths are provided for each filter. Background red is more intense when the proportion of light blocked at given wavelength is higher:

100 – 75 % 70 – 50 % 45 – 25 % 20 – 0 %

Blue light reduction rates of f.lux at different color temperature settings are also included in the table.

Disclosure: some of the links below (principally to Amazon) are commission links: If you use them to go to a vendor’s site, and purchase a product, I get a small commission at no additional cost to you. Thanks for helping sustain GLARminŸ!


Blue light filter
(click to open spectrogram)
Type % blocked at wavelengths (nm) Where to buy
400 425 450 480 520 570
SomniLight Migrane Relief Glasses 100 100 100 100 100 100 SomniLight
Filter 0 – cutoff: 580nm Filter Tester 100 100 100 100 100 100 GLARminY
Carbonshades ** Glasses 100 100 100 100 100 100 Carbonshade, Amazon
NoIR #570 39% Dark Red/Orange Glasses, Clip-ons, Flip-ups, Fit-Overs 100 100 100 100 100 90 NoIR, Amazon
Below closer to Tester Filter 1; above to Tester Filter 0. / Wavelengths: 400 425 450 480 520 570 (nanometers)
Cocoons SideKick orange lens ** Clip-on flip-ups 100 100 100 100 100 n/a Cocoons
NoIR #553 52% Red/Orange Glasses, Clip-ons, Flip-ups, Fit-Overs 100 100 100 100 100 70 NoIR, Amazon
Filter 1 – cutoff: 525nm Filter Tester 100 100 100 100 100 65 GLARminY
3M 2846 Red-Orange safety spectacles Glasses 100 100 100 100 100 55 local 3M distributors
LowBlueLights – glasses Glasses, Fit-overs 100 100 100 100 100 20 LowBlueLights glasses, fitovers
NoIR #60UV 49% Orange Glasses, Clip-ons, Flip-ups, Fit-Overs 100 100 100 100 100 20 NoIR, Amazon
UVEX SCT Orange Glasses, Fit-overs 100 100 100 100 100 15 Amazon
NoIR #505 56% Orange Glasses, Clip-ons, Flip-ups, Fit-Overs 100 100 100 100 95 60 NoIR, Amazon
Spectra 479 Glasses 100 100 100 100 95 40 Spectra479, Amazon
Melatonin Shades Glasses 100 100 100 100 95 30 Melatonin Shades, Amazon
BlueBlockGlasses Glasses 100 100 100 100 95 25 BlueBlockGlasses
f.lux at 1200K * bluelight app 100 100 100 100 95 15 f.lux
LowBlueLights – screen filter Screen protector 100 100 100 100 70 15 LowBlueLights
NoIR #533 35% Amber/Orange Glasses, Clip-ons, Flip-ups, Fit-Overs 100 90 95 95 90 70 NoIR, Amazon
Mojo BluBlock Sun Brown 60 Glasses (also Prescription) 90 90 95 95 90 60 ReadingGlassesETC
NoIR #68 52% Light Orange Glasses, Clip-ons, Flip-ups, Fit-Overs 100 90 90 95 90 10 NoIR, Amazon
Below closer to Tester Filter 2; above to Tester Filter 1. / Wavelengths: 400 425 450 480 520 570 (nanometers)
Filter 2 – cutoff: 490nm Filter Tester 100 100 100 100 25 15 GLARminY
Mojo BluBlock Therapy Orange Rx Glasses 100 100 100 95 85 30 ReadingGlassesETC
Spektrum ProSPEK-99 Glasses, Clip-ons, Flip-ups 100 100 100 95 75 10 Spektrum, Amazon
NoIR #465 70% Yellow Glasses, Clip-ons, Flip-ups, Fit-Overs 100 90 95 85 30 10 NoIR, Amazon
Mojo BluBlock Day Tan Melanin Glasses (also Prescription) 95 90 85 80 65 30 ReadingGlassesETC
Below closer to Tester Filter 3; above to Tester Filter 2. / Wavelengths: 400 425 450 480 520 570 (nanometers)
Cocoons non-polarized yelow/lemon lens ** Fit-overs, Clip-ons, Flip-ups 100 100 100 n/a n/a n/a Cocoons
Filter 3 – cutoff: 460nm Filter Tester 100 100 100 80 15 10 GLARminY
T’aime 97% lens * Glasses 100 100 100 75 20 10 T’aime on Amazon
NoIR #50UV 54% Yellow Glasses, Clip-ons, Flip-ups, Fit-Overs 100 100 100 70 10 10 NoIR, Amazon
f.lux at 1900K * bluelight app 100 100 95 90 80 15 f.lux
Mojo BluBlock Night Yellow Glasses (also Prescription) 100 100 95 70 40 15 ReadingGlassesETC
f.lux at 2300K * bluelight app 100 95 95 80 70 15 f.lux
NoIR #58 58% Yellow Glasses, Clip-ons, Flip-ups, Fit-Overs 100 95 95 30 10 10 NoIR
f.lux at 2700K * bluelight app 100 90 85 70 60 15 f.lux
Mojo BluBlock Day Amber Melanin Glasses (also Prescription) 95 90 80 60 40 25 ReadingGlassesETC
UVEX Amber Glasses, Fit-overs 100 85 75 20 10 10 Amazon
f.lux at 3400K * bluelight app 100 80 75 55 45 15 f.lux
Below closer to Tester Filter 4; above to Tester Filter 3. / Wavelengths: 400 425 450 480 520 570 (nanometers)
Mojo BluBlock Sun Brown 40 Rx Glasses 80 75 80 80 70 40 ReadingGlassesETC
TheraSpecs FL-41 indoor lens Migraine relief/anti-fluorescent Rx Glasses 55 60 80 80 80 45 TheraSpecs, Amazon
Filter 4 (TheraSpecs-like) Filter Tester 65 70 65 75 75 40 GLARminY
Below closer to Tester Filter 5; above to Tester Filter 4. / Wavelengths: 400 425 450 480 520 570 (nanometers)
Filter 5 (GUNNAR-like) Filter Tester 75 60 65 55 35 20 GLARminY
Mojo BluBlock Day Brown 20 Glasses (also Prescription) 70 60 65 65 50 25 ReadingGlassesETC
Reticare – screen filter Screen protector 60 65 65 50 30 20 RetiCare, Amazon
f.lux at 4100K * bluelight app 95 70 60 50 35 15 f.lux
Gunnar Glasses (also Prescription) 100 70 55 25 15 5 Gunnar, Amazon
Spektrum ProSPEK-50 Glasses, Clip-ons, Flip-ups 100 80 45 20 10 5 Spektrum, Amazon
Below closer to Tester Filter 6; above to Tester Filter 5. / Wavelengths: 400 425 450 480 520 570 (nanometers)
Axon FL-41 indoor lens Migraine relief/anti-fluorescent Rx Glasses 100 50 40 45 50 40 Axon, Amazon
Filter 6 (AXON-like) Filter Tester 40 35 40 45 45 30 GLARminY
Below closer to Tester Filter 7; above to Tester Filter 6. / Wavelengths: 400 425 450 480 520 570 (nanometers)
EYES PC Glasses (0, +1, +2 power), Clip-Ons 100 60 35 25 15 10 Amazon
f.lux at 5000K * bluelight app 95 40 35 25 20 15 f.lux
PYEPYD ** Screen protector 100 40 30 n/a n/a n/a PYEPYD, Amazon
BluTech Glasses 100 50 25 20 20 15 n/a
J+S Vision Glasses 100 35 25 15 10 5 Amazon
EYES PC Screen protector 100 30 25 25 25 20 Amazon
JINS Screen Glasses 100 100 20 10 5 5 JINS, Amazon
Filter 7 – Cutoff: 400nm Filter Tester 100 40 20 20 15 15 GLARminY
Gamma Ray: yellow/amber tint Glasses 95 50 20 15 5 0 Amazon
Nikon – SeeCoat Blue Premium Glasses 95 35 15 10 n/a n/a n/a
RetinaShield Screen protector 95 25 15 10 10 10 Tech Armor, Amazon
OcuShield Screen protector 30 15 15 15 15 20 OcuShield
EyeFatigue Glasses 20 15 15 10 5 10 EyeFatigue
PFO Global – iBlu Coat Glasses 95 15 10 10 10 5 n/a
Zeiss – DuraVision BlueProtect Glasses 35 15 10 5 0 0 n/a
Zeiss – DuraVision DriveSafe Glasses 35 15 10 5 0 0 n/a
RetinaGuard Screen protector 95 30 10 10 n/a n/a RetinaGuard, Amazon
SleepShield Screen protector 95 25 10 5 5 5 Amazon
Essilor – Crizal Prevencia Glasses 95 25 10 5 0 0 n/a
Zenni – Beyond UV Glasses (also prescription) 100 50 5 5 5 5 Zenni
Essilor – Smart Blue Filter Glasses 15 35 5 5 n/a n/a n/a
iLLumiShield Screen protector 40 10 5 5 0 0 iLLumiShield, Amazon
* Blue blocking rates at selected wavelengths estimated from before to after spectral power reduction, not from spectral transmission data.

** Sprectral transmission data from vendor’s website

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GLARminŸ Tester care & use instructions


Blue light filter tester-over prescription glasses top-down view L


Size. The good news for those who normally wear glasses is that GLARminŸ Tester fits over normally-sized reading/prescription glasses. In case you want to make sure it will fit over yours: the distance between the temples is 150mm = 5 2932 inches. So if your frame is not wider, you can use the Tester.


Blue light filter Tester 7 year old fit L


The out-of-the-“box” frame size:

  • loosely fits smaller heads (e.g. a 7-year-old; see the above image)
  • tightly fits a larger, adult head, (as wraparounds), which minimizes the possibility of unfiltered ambient light) reaching your eyes (see below).


Blue light filter tester-wraparound fit L


Adjusting temple size. It is advisable you try GLARminŸ Tester before adjusting its size. If you need longer temples, increase their length carefully with scissors, as shown below. To guide you in cutting, use the indicating cuts.


How to clean filters: To clean a Filter, first take it carefully out of the frame to avoid any damages to the cardstock frame.

Filters are made of transparent polyester with a tinted surface coating. The coating is what gives the Filter its unique spectral properties. It is, therefore, important not to damage it either mechanically (by using rough cloth) or chemically. The coating may be affected by solvents such as acetone or ethanol!

Use water-based cleaning solution. Use a gentle, lint-free cleaning cloth (microfiber cloth), or a gentle facial tissue (Kleenex). For example, you can use most water diluted liquid soaps to clean the Filters. Rinse under running water. Dry with facial tissue.

Perspiring & liquids. Sweat or other liquids applied to the cardstock frame will deteriorate it. Refrain from using GLARminŸ Tester when sweating and keep it away from liquids.

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Ps: If you found GLARminŸ Tester: Pick your blue block eyewear or screen filter best-informed useful, please consider LIKING, REBLOGGING, and/or SHARING it below.