When you use your laptop (or any screen for that matter) for a long period of time, you’ll obviously get digital eye strain symptoms, sometimes referred to as computer vision syndrome. But why exactly does this happen, and what can you do about it?
Why do I get Digital Eye Strain?
We all know how light travels from the environment into your eyes to help you see. Light is refracted twice, at the cornea and at the lens, then focused onto your retina. There are muscles and ligaments particularly supporting your lens which adjust depending on how far the object you’re trying to see is. In the case of a laptop, you’re trying to visualize a near object, which is at a font way smaller compared to an ad billboard on the highway. So, the muscles supporting your lens contract making the lens more spherical, your pupillary muscles contract making your pupil smaller, and your medial eyeball muscles contract converging your eyesight to your laptop screen.
These reflexes are meant to help you focus and see clearly. However, maintaining all these contracted muscles continuously for a long period of laptop focus time (more than 1 hour) is a very high-demand situation for your eyes. And that’s why digital eye strain symptoms appear. Symptoms such as dry eyes, eye ache, headache, tearing, blurred vision and increased sensitivity to light.
What can I do about it?
1. Balance your screen brightness and ambient lighting
Some reasons why people set their screen brightness high is because it increases their speed of reading because of faster saccades (the rapid eye movements as you shift from one screen point to the next), as well as enhanced visibility of displayed content. However, when it’s too bright, the faster saccades unconsciously cause reduced blinking frequency, resulting in dry eyes, tearing, and eye ache. The reverse is true when you set your screen brightness too low.
On the other hand, high ambient illuminance allows one shorter reaction times while reading, hence improved efficiency in processing visual information, as well as enhanced overall visibility of the environment, say if you’re using your notebook to take down some notes. However, when it’s too bright, there will be glare or a reflection on your laptop screen, and you won’t see clearly especially if you’re using your screen in dark mode. The reverse is true when your ambient light is too low.
So the trick here lies in balancing these two sources of light. You don’t want either your laptop screen light or your ambient lighting to be higher or lower than the other. Some people opt to have the lights on during the day, while some opt to sit near a window. Some people opt for the laptop screen dark mode, especially when ambient lighting is very low and sort of out of your control, like your assigned office desk. Whichever works for you, the key lies in balancing these two light sources.
2. The 20-20-20 technique
There’s a technique called 20-20-20. This is where every 20 minutes, one takes a break from the laptop screen and gazes at something that’s 20 feet away (6 meters) for about 20 seconds before continuing with work. This technique helps relax the 3 muscle groups described above and reduces the prolonged straining of said muscles. It also helps promote blinking of one’s eyes because when on your screen, blinking frequency unconsciously tends to reduce by about 60%, due to the high cognitive demand and frequent saccades.
Perhaps within these 20 seconds, walk to the water dispenser to refill your glass of water or say hi to your colleague.
When I was preparing for this piece, I talked to my office colleagues about this 20-20-20 technique and some said it might not always be practically possible because of the work load on some days or the high risk of breaking the creative flow. When I checked, I couldn’t find any research-proven alternative to this technique published yet, so there goes another research paper problem statement. 🙂
3. In the evening, get yourself some blue-block glasses
The blue light from your screen affects more of your body’s circadian rhythm, rather than harming your eyes. The circadian rhythm is responsible for your sleep cycle and altering it makes it harder for you to sleep. So do use some blue block glasses in the evening. The night-light for your laptop screen also does reduce blue light exposure, is more comfortable for your eyes when in low light environments and reduces difficulty in falling asleep at night.