Blog – Koert-Jan.nl

EyesApril 15, 2021April 15, 2021

After posting my last article about choosing a new monitor, I received some questions regarding a good choice for a mobile device or screen. Not unsurprisingly, as I also use my phone more frequently than a computer.

The thing is, that I already bought a new phone about six months ago. And at that time I wasn’t aware of the different screen limitations and techniques Most of the monitor insights however, also apply to mobile screens as they largely use the same technology. So inherently they are subject to the same drawbacks, like “flicker”. Huh what is flicker?! If you don’t know what I’m talking about, please check out my previous article here which goes more in depth

Read : As a deer in the headlights — New monitor considerations

Nevertheless I did slightly change the way I use my phone after the new insights. So here is a quick rundown of stuff I do to help brain out a little bit. Focused exclusively on mobile screens. I don’t have any experience with Android devices so most of the info is primarily aimed at Apple/iOS, although the parity between the two platforms will ensure that these tips probably will be applicable for both.

First thing is checking the flicker (test) data, preferably before buying The most comprehensive overview I could find regarding this subject is at Notebookcheck [1]. Luckily in hindsight my new-ish iPhone SE 2020 is a great choice, as it tested flicker free

The data is not exclusive to Apple devices or mobile phones for that matter, you can even check out laptops and monitors which is also very handy of course. Highly recommended

As you may already understand that flicker is a complicated subject and which can be influenced by a lot of factors like for instance the brightness . So it may be worth your while to search for your phone’s optimal setting. See the video below for a great example of how a brightness can influence flicker.

As you can see, the iPhones that use an OLED display don’t fare so well. As their flicker frequency is quite high this may not be an issue for everyone. However after some googling I definitely found anecdotal reports of increased eye strain and headaches when upgrading to this iPhone version from a previous flicker free one. So for me, given the choice I would opt for a flicker free one from the list

I always use night shift mode, even during the day. Night Shift automatically adjusts the colors of your display to the warmer end of the spectrum, making the display easier on your eyes. You do lose some of the contrast and vibrancy, but who cares. My selfies are still majestic

I use accessibility features to quickly switch to different color settings. When I have to read from my phone I like to keep the colors to a minimum as it doesn’t add anything and limits my ability to focus. That’s why I created a shortcut (three presses of the home button) to switch to greyscale mode. It’s super easy and quick to do so I actually use it all the time [2].

An unexpected side effect of using grayscale mode is the reduction of time I mindlessly spend scrolling on social media. Probably this has something to do with the fact that when everything is not super vibrant, and poppin’. My brain thinks “Why am I looking at this shit…? Go outside!”

You can also use accessibility features to change the color filter to reduce blue light [3]. Blue light is something that can disturb your sleep-wake cycle, especially at night. Unfortunately you can only have one color filter shortcut as far as I know of, so I opted for the greyscale mode as I use that more often.

I always use Dark Mode when possible. Dark Mode is aimed at a better and easier viewing experience during low light conditions. However I noticed that for me it feels better all the time 😉 Keep in mind that sometimes you have to set this separately for an application.

So that’s the quick rundown regarding mobile screens. If you have any other suggestions please let me know.

[1] Notebookcheck PWM Ranking – The Best Displays for the Eyes
[2] Biohackerslab What Are the Blue Light Filter Options for an iPhone?
[3] iGEEKSBLOG How to Use Color Filters on iPhone and iPad

EyesApril 2, 2021April 6, 2021

The ability to concentrate is still one of the most challenging things for me. This becomes especially apparent when reading or writing of a screen or monitor. You can imagine that this is hard to work around in daily life. So anything that can help alleviate this challenge is very welcome.

After looking into different (mostly technical) details of modern monitors. I found a couple of things that could be helpful regarding the amount of strain I (and we all) put on our brain and eyes during use. Crazy fact, our eyes are actually part of our brain outside of the skull But anyhow…

Without making things overly complicated these are some points that stand out for me in a sea of technical specifications and confounding factors. Like the brain a modern day monitor is pretty complicated, so bear with me. Or you can just scroll down for the takeaways

One the one most important things is called “flicker”. Flicker in layman terms is a light source that isn’t completely stable or constant. Sort of like a flashlight repeatedly switching on and off. It blinks, or for lack of a better word it flickers You can imagine looking into such a light for longer periods of time wouldn’t be really all that pleasant. But this is actually what we’re doing when using a monitor, albeit in a way less obvious and subtle manner. It is just an inherent drawback of how a modern monitor works. A lot of things can influence the amount of flicker your monitor or screen has and here are but a few.

The first one is the refresh rate. The refresh rate is the number of times per second that your monitor displays a new image. This is written in Hertz but often abbreviated as Hz. Most monitors have a refresh rate of 60Hz. So 60 times per second a new image called a frame, will be displayed.

Among other things, the switching between the old and new frames can create flicker. It happens so fast that your brain stitches it all together so it still looks as one continuous image. You probably won’t notice this but it’s putting extra stress on our brain to process this subtle flashing light source. In recent years more expensive monitors have been released with higher refresh rates like 120 or even 240Hz, and so creating less flicker.

Most hardware today is actually capable of flicker free operation, but because manufacturers use certain technology to extend the life and energy efficiency of a monitor, this is still an issue.

The higher refresh rate also gives the advantage of increased fluidity when motion occurs. Whenever I’m looking at a screen I get instantly nauseous when there is a stutter during a camera pan, a roller coaster feeling if you will. With an increased refresh rate you get more frames or steps to a movement and it feels way easier for my brain to comprehend and process what I’m seeing.

Below a video to illustrate the effect of increased fluidity when the number of frames increases. You probably can’t see the difference between 60 and 120 frames as your screen could very well be the limiting factor, if it’s running at 60Hz.

Another flicker related thing is the brightness. I used to lower the brightness all the way down, not knowing this could be introducing extra flicker due to the hardware design of the monitor. There are two main methods to lower the brightness of a screen. Long story short; the Direct Current (DC) dimming method is the preferred one.

The other method Pulse Width Modulation (PWM) method works by quickly switching off for a period of time when a new image is displayed. So at 30% brightness, the screen is turned off 70% of the time. This happens at the refresh rate (typically 60Hz), so very fast. Again you won’t notice this, your brain and eyes just see a seemingly still image. But in the background all of this is happening constantly. Of course this is something that should be avoided as this will increase the discernible strobe-like light effect.

The DC method however has the advantage that it dims the screen by giving the LEDs/crystals in the display less electrical current in which the screen will simply light up less brightly. That way it doesn’t introduce any extra flicker. So that’s why the DC method is favored in my particular case. However…

If you already have a monitor which uses the PWM method you can also dim your screen via a handy app, called Iris (see footnote). It’s about 15 euro and it’s well worth it. Almost all monitors use the PWM method as it is cheaper to manufacture, so unless you have a high-end one that specifically states it’s using DC dimming, you can assume you would benefit by dimming your screen via this app instead of the physical buttons located on the monitor itself.

Next to that it also has multiple handy features which I use all the time. It can for instance adjust your screen’s color balance based on the time of day. That way it blocks most of the blue light entering your eyes at night. Blue light in the evening disrupts your natural sleep rhythm. That’s a whole different and extensive subject, let me know if you want to know more as I can write up a separate article for that.

Also it helps me with taking (micro) breaks through it’s built in timer. Every 2 minutes my screen shows an overlay letting me know that I have to look away from the screen and focus on something in the distance. So that way my eyes can relax a little bit. You can of course change the timer to a longer interval which I imagine suites less visually challenged people I found this very helpful in extending the time I can spend doing computer stuff. Who knew that taking short breaks actually works

Check out this TEDx presentation by Daniel Georgiev, the software engineer who created the Iris app for a further deep dive into the workings of modern monitors.

Last thing I considered when buying a new monitor is the screen’s finish. You may have noticed that some laptop screens have these high gloss finishes, which will increase the contrast and color vibrance. It looks really good, but the extra reflective surface makes it difficult to focus on the screen. You instead switch between focusing on the reflections and the stuff on the screen itself. My neuro-optometrist compared it to reading from a mirror.

The other option is called matte finish, which will almost be reflective free. Some manufacturers even let you choose between the two when buying a new monitor or laptop. So definitely a matte finish for me 😵

So to summarize my main takeaways

High refresh rate, preferably 120 Hz or higher to reduce flicker and increase more natural motion

Get a monitor with DC dimming or use a special program like Iris to control the brightness of your screen

Opt for a matte screen finish to limit reflections

I ended up with a 27″ QHD monitor by LG (model: 27GL850). Besides a good refresh rate of 144Hz and DC dimming, it also comes highly recommended in other categories like color accuracy and ergonomics.

And Oh boy… I really should have bought this earlier. I now have a lot less headaches and I’m able to spend some time behind a computer for once. The higher refresh rate really makes a ton of difference for me. When I set the monitor to a lower refresh rate like 60Hz. The image looks way more “jittery” and uneasy. It’s actually a bit hard to describe.

So if you are experiencing any symptoms like headache, fatigue or other visual challenges after monitor use. It could be worthwhile to take a look at these three things in particular.

Ps. I did also check out e-paper monitors. Which would actually be perfect for me, as they use a completely different screen technology. Think e-reader screen, but bigger. Unfortunately, due to the high price and limited availability, they are currently not a viable option for me.

Let me know if you have any other suggestions for helping out the brain when using a monitor

Iris, blue light filter and eye protection Software: https://iristech.co/

RecoveryMarch 7, 2021March 12, 2021

I’m electrocuting myself on a regular basis…🤯!? It’s called Transcutaneous Vagus Nerve Stimulation (tVNS) and It’s a way to access and modulate my brain with the help of some microcurrent.

So I’m stimulating this “vagus nerve”, but what is it exactly? The vagus nerve is one of the longest and most intricate nerves of our body. It runs from the brain all the way down to the major organs. The nerve is crucial in regulating much of the involuntary processes of the body, such as heart rate, breathing, digestion and immune system response. Sub optimal vagus nerve activation has been linked to impaired cognitive ability, inflammation and depression among others.

By stimulating a specific part of the vagus nerve located in the left ear, it can activate several restorative pathways. This particular left ear application focuses on the parasympathetic branch of the nervous system that is mainly associated with relaxation and recovery.

An unexpected side effect is that when meditating, it quickly brings me into a super deep state of relaxation, which makes it very powerful to unwind even more if I’m willing to make an extra effort.

When in use, you just feel a little tingling in your ear. You can also tweak the settings so that you don’t notice it at all. Either way it isn’t even distracting, except for the persons around you of course

There are quite some devices that basically all do the same thing. At first I was looking at a premium option (parasym.co) that included an accompanying sound therapy for tinnitus (which I also struggle with), but the high price put me off.

Then I stumbled upon a dutch company selling a prototype earpiece especially designed for this purpose. The earpiece runs about €90 and can easily be hooked up to a control unit from the same company, which you have to buy separately.

Update 11.03.21 Unfortunately the company discontinued the product recently. You can still get the other premium option that I mentioned before.

There is also the option of a very cheap universal clip which you click on your ear. I haven’t tried this myself as according to the research precise placement is key so a more custom earpiece seems like a smart choice. Also comfort comes into play, as securely clamping something on my ear for longer periods of time doesn’t seem that appealing.

The control unit provides the actual microcurrent. I really wanted granular control for a precise tuning as I’m sending current through my body. So I ended up with a more expensive device that I initially was planning to, but in hindsight I’m glad I did. The small half current steps are really subtle and I use them all the time. This particular unit is about €250 and is called the TENS eco 2 by Schwa-Medico.

I have experimented a lot with the settings and depending on my mood and goal, I usually end up between 10 and 25Hz with a microcurrent of around 2 microamps (mA). That 2 mA is often the threshold to just feel a little tingling in my ear. One thing I have noticed is that the higher my cognitive fatigue the more microcurrent I have to use to “feel” the effects. In those situations I have used around 5 mA for a short period of time.

You can do multiple sessions per day, but like mentioned I regularly do just one in the evening ranging between 15 to 60 minutes. There are also good guidelines provided in the earpiece manual.

In the footnote, you can find some research papers which provide extra background information and the settings that were used in the clinical situations.

You can also activate the same vagus nerve pathways in more traditional ways. Gargling with water, humming and especially singing should work. Although from my experience these are way less effective. But this could very well be related to the quality of my singing 😉

Has anyone else tried (this type of) neuromodulation? Please share, as I think it can be very helpful for others with the same challenges

Steenbergen L., Sellaro R., Stock A.K., Verkuil B., Beste C. & Colzato L.S. (2015), Transcutaneous vagus nerve stimulation (tVNS) enhances response selection during action cascading processes, European Neuropsychopharmacology 25(6): 773-778.

Colzato, L. S., Ritter, S. M., & Steenbergen, L. (2018). Transcutaneous vagus nerve stimulation (tVNS) enhances divergent thinking. Neuropsychologia, 111, 72-76

Fang J, Rong P, Hong Y, et al. Transcutaneous Vagus Nerve Stimulation Modulates Default Mode Network in Major Depressive Disorder. Biol Psychiatry 2016;79:266–73. doi:10.1016/j.biopsych.2015.03.025

Goldberger JJ, Challapalli S, Tung R, et al. Relationship of Heart Rate Variability to Parasympathetic Effect. Circulation 2001;103:1977–83. doi:10.1161/01.CIR.103.15.1977