Limitations of sight
I think displays are hitting a point where very soon, the display resolution will be way beyond the capabilities of human vision. After this, the next logical step would be to again divide each pixel into 4, and that would definitely be way beyond what the eye can see (if we're not already there with this technology!)
We're pretty much there already. I can barely see the difference in pixel density of my Nexus 2012 and 2013. Even though it has a higher resolution display and higher pixel density, I'm hard pressed to see a night and day difference. At normal viewing...