Curing dry eyes and work-related eye strain or headaches

For many years I had severe dry eye syndrome and constant burning sensation behind my eyeballs. A couple of years ago I finally found out what’s the problem and I solved it once and for all. Let me share how!

A combination of factors

In my particular case there were many factors which contributed. My approach turned out to be quite complex, but in the end it worked flawlessly.

Displays without PWM

My eyes turned out super sensitive to displays with PWM or Pulse-width modulation. I won’t go into details, but you can understand the issue here:

Pulse Width Modulation by TFTCentral

In Bulgarian: Трептенето на дисплея в следствие на ШИМ by RMania

Gradually I replaced my monitors, TV, smartphone, tablet and home lights with non-flickering alternatives. Before buying new displays of any kind, I research whether it has PWM controlled backlight. An increasing number of review websites like and include PWM measurements.

I also built a mobile oscilloscope to measure any flickering myself. It is super simple. The idea is that there are oscilloscope apps for Android which plot the sound wave from the smartphone’s microphone. If I plug in a photodiode which generates electric waves from flickering light and connect it to the microphone input, I can visualize the flickering on my smartphone.

I used an Osram BPW34 photodiode and a single (or two) 100K Ohm/1W resistors connected in series. Depending on your phone you might not need the resistors or you might need less/more. You can see the diode, the resistors and the 3.5mm -> USB C adapter as my phone lacks 3.5mm jack.

The app I’m using is Oscope, but there are many good ones out there.

A lot of people suffer from PWM controlled backlights and I hope that awareness of this issue fill grow.

Another technique I’m using to detect flickering is to set my phone’s camera shutter speed to the fastest possible. It is very efficient at detecting flickering displays and lightbulbs. I use Osram LED lightbulbs in my house and they don’t flicker.

One manufacturer which doesn’t seem to care about PWM at all even in 2020 is Samsung. Virtually all of their smartphones, tablets and TVs use PWM and flicker a lot.

This problem took forever to insulate, but was very important.

Blocking eye tear ducts

It turned out that either my tear glands don’t produce enough tears or my tear duct channels are too wide. The net result was that the tears on the eye surface was insufficient and the tear film broke out too quickly, leaving the eye dry.

There are a lot of people with similar problems and they think that artificial teardrops are the solution. But they are not. The real solution is to block one of the tear ducts or both of them. This way the tears will stay on the eye’s surface for longer and you won’t experience discomfort. The procedure is performed in a hospital and lasts 15 minutes or so. The doctor inserts hydrogel plugs inside the holes through which the tears are drained. I blocked only my lower ones. It is the lower “Puncta” in this picture. This might seem like a very invasive and scary procedure, but it is not. It was a life savior for me. I almost never experienced eye dry symptoms afterward. Before the procedure, I wasn’t able to work for more than 4 hours straight in front of a monitor.

This problem was a very obscure one. I went to countless doctors for almost a decade and no one seemed to know or recommend this solution. For 150 EUR and several hours in the hospital I solved one of the biggest problems in my life. The procedure is also reversible, in case you are scared.

Training to blink more often

I contacted the developer of Eyeblink early in his endeavor to help a lot of people with this revolutionary app and served as an early alpha/beta tester. Eyeblink uses your web camera, detects your eyes and counts how often you are blinking.

If your blinking rate decreases, the app reminds you to blink. As this process happens tens to hundreds of times during a typical working day, your brain gets trained and begins to blink more often. It really works!

Taking regular breaks

Eyeblink also reminds me to take short and long breaks. Before that, I used Eyeleo for this purpose.

I regularly take rests between my pomodoro sessions and this helps a lot too.

Wearing eyeglasses

As simple as this might sound, wearing eyeglasses to correct even minor focus power or astigmatism is sometimes necessary. I have a really low +0.25/+0.50 diopters are a little bit of astigmatism that I don’t normally mind at all. My sight as far as I’m concerned is near perfect.

However, if I try to work without glasses for even those seemingly minor corrections, my eyes begin to hurt in an hour or so.

Bonus: Pollen allergy

Lately, I realized that I have a pollen allergy and during a month in the spring, my eyelids become really swollen and I feel my eyes very, very dry. Fortunately, it turned out that Xiaomi Air Purifier 3H works like a charm to filter the pollens! I bought a couple of them – two for my apartment and one when I need to be in an office. I leave them turned on during the winter when the PM2.5 particles become an issue in Sofia. More importantly, it turned out that they filter pretty good the pollens from the air and provide relief in half an hour for my eyes after pollen exposure outside too!


Displays without PWM, blocking tear ducts, blinking often, taking rests, wearing eyeglasses and taking care of allergies. This might seem like a lot, but it is well worth it. I managed to solve a problem that plagued me for years and as I said before, it turned out a pretty complicated solution. I really hope this information might help you as well!

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