Video: One simple test to check how good your eyesight is
How quickly you can spot Albert Einstein is the key to how sharp your vision is
All you need to do is watch this video and pay attention to the image as it comes towards you.
The quicker you can spot Albert Einstein from Marilyn Monroe, the better your eyes are.
If, by the end of the video you can't see the scientist, then you need to go to the optician.
As for the science of this, the guys in the video explain it perfectly.