Is there a better way to start with this blog than this breathtaking work by the MIT? Aiming at emphasizing tiny motions inside videos, their approach allows to recover and magnify subtle changes that a human eye cannot perceive.

I can only advise you to have a look on the TED talk held in 2014, where you will see a baby heartbeat, the deformation of a glass in presence of sound, and other fun/creepy things that will make you understand how little our eyes can actually see.