Quoting a previous comment of mine (https://news.ycombinator.com/item?id=42796950#42797424)
> A big thing not often spoken about with eye strain is dry eye caused by the lack of blinking due to focusing on screens too close to our face. This is an evolutionary phenomenon--close dangers cause extreme focus without blinking. Extreme focus on close items reduces our blinks. Our eye lids have glands in them that release oils on your eye with each blink. These oils help prevent the watery part of your tears from evaporating. When it evaporates your eyes dry out causing discomfort and potentially pain.
> If you don't blink enough, the oil doesnt get on your eyes and eventually, in extreme cases, the glands can even die. A lack of oil in tears can cause extreme eye fatigue and even pain.
> This is why dry eyes is on the rise. Remember to blink!
> I actually built a little web app to count my blinks. See https://dryeyestuff.com/. Not perfect, just a prototype. 100% free.