when you are holding f5, it spams in a way, where it hurts peoples eyes.
this is present only in singleplayer (correction: i just went onto a popular server and tried it. it works on that version.)
this stops when you move around. by pressing the following keys:
w, a, s, d, f1, f3, e.
the video is quite compressed: cus of 10mb limit.
this needs a fix.
try this out.
Duplicate of MC-118107