But tbh, if I play some relaxing game in which I don't focus so much, I don't mind having a bit lower FPS. Also, I said higher FPS won't tire your eye as much, not lower, that is basically because your eye "will see" more pictures in the same time so it will feel closer to real motior. Also, you gotta have a good enough monitor with high refresh rate to see that.
For me, I play a lot of Counter-strike and I can see difference between some fps, for example, if I have only 30, then the game doesn't feel so smooth and aiming becomes harder. That's also why most of people who are really keen on CS have 120hz+ monitors. (if you play cs by a chance you can just limit fps by typing "fps_max *number*" in console).
Your eye can't really see 60 fps. It will see pictures not as pictures, but as motion when displayed at 30 fps and higher. Higher fps in games only makes the game feel smoother and won't tire your eyes as much.
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