No, my eyesight both far and close was quite a bit better than average as of last week (as I was just there getting checked). We have a lot of 4k and 5k displays at work and most people who say they can tell a (significant) difference when we compare (the topic comes up a lot) seem to usually either be on > 27inch, have scaling higher than what's expected, or just fail to see it when we really test it out. Your millage may vary :)

Don't get me wrong, I can see a difference, but not nearly as night and day, especially when it comes at the cost of other features (eg refresh rate... which isn't the end of the world for coding so if it's the only thing you do on the monitor it could be worse... otherwise ouch my eyes.)