re-timer glasses review

We got our hands on the Re-Timer glasses, a futuristic-looking pair of light therapy glasses, and put them through some testing to see how they stacked up against the competition!

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The aim of light therapy products is to align your circadian rhythm and alleviate the symptoms of insomnia, depression, and seasonal affective disorder.

Let’s dig in!

The Re-Timer Glasses

The Re-Timers are light therapy glasses invented by Professor Leon Lack and Dr. Helen Wright.

These glasses underwent hundreds of design iterations and years of development and what they came up with is just wild looking!

retimer glasses product photo

The idea with the design was to eliminate the eyebrows from blocking any light.

What we’re left with is a strange pair of headwear you probably won’t want to wear in public, unless you want a lot of attention…

We’ve done a video review too if that’s more your style:

The Re-Timer comes packaged in its own carrying case…

re-timer package contents
Here’s what you get!

Inside you’ll find:

  • The Re-Timer glasses
  • Soft carrying pouch
  • Mini USB charging cable
  • And the trusty instruction manual

If you let out a gasp at “Mini-USB” I wouldn’t blame you, I have to admit I was quite disappointed with this… USB-C, please! Or lord at least give us Micro-USB, who has a mini USB nowadays?

re-timer charging port and cable
Sigh. Who’s idea was this?

At least the battery life is good!

The rated battery life of 6 hours should give you at least a week of usage in between charges, plenty for most trips if you need it for that.

The carrying case they come with is quite large but if that doesn’t bother you it’s nice that it comes with one!


  • Weight: 75g
  • Warranty: 1 year
  • LED Color: Green-turquoise
  • Session time: 30-60 mins
  • Battery life: 6 hours
  • Charge time: 3.5 hours
  • Guarantee: 30 days

To give you an idea how the size of the case, here it is compared to the AYO’s case:

top view of the ayo case compared to the retimer case
Top view
side view of the ayo case compared to the retimer case
Side view

So if you’re low on space and are looking for a pair of light therapy glasses for traveling, the AYO+ would be the better choice!

How Effective Is the Re-Timer?

The team behind the Re-Timer glasses has done a splendid job putting these through numerous studies. But before we go over some of those, let’s do some testing of our own!

In order to compare the Re-Timer glasses to other options on the market we put it on our test mannequin Henry!

This allows us to get lab-grade spectral readings at eye level.

Re-timer glasses being worn by our spectrometer equipped mannequin head

The Re-Timer uses 4 slightly diffused green-turquoise LEDs to activate your circadian rhythm.

image of retimer leds
I really wish they were more diffused, however…

Here’s a spectral reading of these LEDs which seem to be peaking at around 501 nm, which is just to the right of the melanopsin bell curve peak.

spectral power distribution graph of re-timer light therapy glasses
Spectral power distribution graph of the Re-Timer glasses
spectrum of re-timer glasses compared with a melanopic bell curve

We took various readings of the Re-Timer glasses using Henry and got the following specifications:

Re-Timer Measurements

  • Brightness: 260-530 lux
  • Total Power: 85-172 µW/cm2
  • Circadian Light: 619-1311 CLA
  • Circadian Stimulus (30 min): 0.454-0.566
  • Melanopic EDI: 539-1098

This varies depending on how you adjust the Re-Timer and which setting is used.

As you can see, if you compare the Re-Timers to something like the AYO, it’s immediately apparent just how much brighter the Re-Timers are, by almost 4x!

However, the AYO+ is still putting a lot more power on its highest setting. With the Re-Timer’s peaking at 172 µW/cm2 and the AYO’s peaking at 229 µW/cm2.

The reason the Re-Timer is so much brighter than the AYO even with a lower power output is that the human eye is far more visually sensitive to green light than blue.

To get that kind of power at eye level from the Re-Timer however you have to be uncomfortably close to it, so I’d say under normal circumstances, the AYO actually wins here.

But overall:

The Re-Timers exceed all minimum circadian requirements with these specs, definitely, nothing to worry about here.

Clinical Trials

Where the Re-Timer glasses really shine (no pun intended) is that they’ve been used clinically in a large number of independent studies.

On their website, you can find eight different independent studies their glasses have been used.

These studies range from treating PTSD depression symptoms to enhancing sports performance, cancer-related sleep disturbance, postpartum depression, decreasing jetlag, and more!

So be sure to check those out if you’re curious!

Re-Timer also links to several of their own research papers.

One such study involved the final Re-Timer glasses and 12 total participants.

The participants were split into two groups, one group would use the Re-Timer glasses for 1 hour at the high setting, while the other group used nothing.

It was shown that using the Re-Timers in this manner shifted the dim light melatonin onset by about 46 minutes over the course of two days of use, while the control group shifted by only 3 minutes.

re-timer study graph of melatonin concentrations following use of device over two nights
Melatonin concentrations from two consecutive nights of Re-Timer use.

What’s It Like Using It?

Using the Re-Timer is pretty straightforward. To turn them on you just have to press the large round button on the inside right of the glasses.

power button and brightness levels of retimer glasses
Power button next to the battery and brightness levels LEDs. Buy Re-Timer

This will turn on the half brightness mode, simply press this button once more to get to full brightness, and once more again to turn them off.

These weigh in at around 75g making them about two and a half times as heavy as the AYO glasses we reviewed.

A Few Things I Didn’t Like…

I found the 4 LEDs a bit glaring. It’s not too bad on the half-brightness setting but I found myself left with temporary photobleaching or retinal staining.

These are basically dark spots in my vision where the green LEDs once were.

So suffice it to say I found the high brightness setting mildly uncomfortable.

Beyond the actual brightness, I found the location of the LEDs to be very inconvenient.

They’re right in your way if you’re reading, typing, or using your phone, I’m just not a big fan of the design personally.

I also found that I couldn’t rest the glasses on my ears as the thin plastic began to cause my ears to ache. So I had to make sure to tilt them slightly upwards.

photo of me wearing re-timer glasses
Here’s me wearing the Re-Timers! They are quite bright. Buy Re-Timer

As long as I didn’t jump around they stayed where I put them.

Unlike the AYO glasses, you certainly won’t be exercising in these due to their weight and design, they’ll just come flying off!

The last issue I have is with the slightly flimsy nose adjustment piece. It’s not horrible, but it’s rather easy to accidentally bump the glasses and lose your adjustment as it doesn’t stay in place very well.

For example, if I was digging out eye gunk after waking up, I would almost certainly mess up my positioning of the nosepiece, which can get a little annoying.

Final Thoughts

Overall, the Re-Timer glasses aren’t for me, while they’re definitely effective, I’m just not a big fan of the form factor and the LED placement.

These would however be a great choice for anyone who wears prescription glasses.

Since they emit a more green 500 nm wavelength light, the blue blocking film on most glasses nowadays won’t have an impact on the light coming from the Re-Timer, unlike the AYO for example which is negatively impacted by glasses.

Re-Timer Light Therapy Glasses

retimer glasses product photo


  • Effective unique spectrum
  • Design works well with glasses users
  • Lots of independent studies prove its effectiveness


  • I found the LED locations uncomfortable
  • Design is a bit out there and can draw a lot of attention
  • Not as effective as AYO or Luminette

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Now check out our guide on 19 Ways to Align Your Circadian Rhythm for more tips on how to get better sleep!

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