Computer Screen Killing Your Eyes? Here, The EYE STRAIN TEST

Computer screens are absolutely the #1 way to ruin your eyesight.   Not that screens are inherently evil.  You can use them responsibly, and keep absolutely great eyesight.  The key is knowing when you strain your […]

Jake Steiner

May 06,2016 · 5 min read

Computer screens are absolutely the #1 way to ruin your eyesight.  

Not that screens are inherently evil.  You can use them responsibly, and keep absolutely great eyesight.  The key is knowing when you strain your eyes so you can take steps to stop vision problems from developing!

You likely already know I reversed 5 diopters of my own myopia.  You probably also know that extended close-up use is the #1 cause of the first stages of myopia.  You probably also know that I spend quite a bit of time in front of computer.  

So, how do I get away with lots of screen time, while also keeping all my 20/20 gains?

How you have your computer set up, is really important.  Let me show you how I set up my work environment for healthy eyesight, to illustrate the key points and show you my strain test.


Reference clarity – more on that in a moment.

So above image, that’s my setup right now, at a coffee shop.

Of course your setup won’t be the same as mine.  But for the sake of understanding what you need, and the ideal scenario, let’s use this one.  Two key points here:

#1:  Full Spectrum Natural Light

First and most important, what we’ve got here is good ambient natural daylight.  

Everything in front of me is glass, and it’s all natural daylight.  My screen brightness is actually set (subjectively, not using a LUX meter) to ambient brightness.  Remember the 1,000 LUX rule?  Whenever I work in front of a computer screen, I absolutely prioritize having full spectrum, natural ambient light to minimize computer eye strain.

And if you think natural light doesn’t matter all that much, I’ve got a simple test for you:  

Find some good ambient natural lighting.  Grab your laptop, take it there.  Take off your glasses and get close enough to your screen that all text is perfectly clear.  Move back very slowly, until you see the smallest bit of blur.  Note this distance (use a piece of paper to mark the distance from the side of your eye socket, to your screen).  

Now try the same thing under some fluorescent lights, and also try it with a dark environment, just the bright computer screen.

(All this goes back to visual acuity, and how centimeters are directly correlated to the diopter prescription of your glasses – see here and here.)

#2: Reference Visual Acuity

The second important ingredient, is having a way to check reference visual acuity (or, how clearly you can see at a distance).   This is your eye strain test.   

When you look up-close for extended periods, the focusing muscle in your eye becomes strained (since it’s tense during close-up vision).  This isn’t a problem in itself, as long as you have a way to recognize it (and then take steps to give it time to relax).  

So I try to be in a place where I can look outside, and have small distant writing available for my eyes.

When I start to work, I check my reference clarity.  How clear is the writing, and how quickly do my eyes focus on it (that second part, also a handy way to tell how relaxed your ciliary muscle is).  During work, once in a while I’ll look up, and see the distant signs.  Still clear?  Doing this just once every hour or so is plenty, to keep giving me a reference of eye strain.

Important note:  If you are still stuck in the mainstream optometry single prescription paradigm (the massive fallacy from 16th century dark ages medicine, the “one pair of glasses for all distances”), then this won’t work for you.  You’ll have to go back a step, and first figure out a less dangerous, appropriate lower prescription for your close-up use.  Important, this, to keep your eyes healthy!

Once I look up and the signs look blurry or it takes my eyes longer than before to focus on them clearly, I know my focusing muscles are strained.

It’s time to get outside for a walk, not be focused up-close.

I can then check how effective my walk was to reduce eye strain, by checking whether my eyes are back to focusing quickly and clearly on the distant signs outside of my work space.  Everything good?  It’s just a few second glance away, and I always know whether my eyes are happy.

Now it’s your turn.  

How close, or far are you from this ideal scenario?  How can you adjust your own close-up environment for better ambient light, and to give you reference acuity?  It could be as simple as buying some full spectrum UV bulbs and sneaking a motivational kitten poster on the far wall!  (though ideally, a window, and real natural light would be the goal to pursue)

Keep those eyes healthy!

Housekeeping:  Session Group 16 update is complete.  We’re almost through all of the updates!


Also, you can find me in Hong Kong next week.  Strictly speaking it’s not an @endmyopia social visit, rather a conspicuous shopping and friends meetup visit.  Still, always glad to chat with students!  Drop me a line in the forum for meetup times.




Jake Steiner

Investor, adventure hunter. BJJ, kite surf, wing foil, paraglide. Off-grid living survivor. Also former myope.

Topic:  Nearsighted: Q&A

Nearsighted: Q&A