this is from another tumblr and it says that if you follow the paintbrush with your eyes without moving your head, it forces you to do emdr which is a therapeutic technique to calm anxiety/panic. 
i actually rly like this and think its actually kinda calming.
woo!
reblog/like/follow cuz im going stalking!
i was rly happy to find this cuz i just love these kind of things :P