What’s cool is the brain fills it in, so you don’t even realize it’s there.  The way I first confirmed that there’s a blind spot was in a pitch black room with one small light.  I shut one eye and ended up getting the blind spot in line with the small light, so that it was completely dark.  The trick is, the blind spot is in your peripheral vision, so you can’t even just look at the light with an eye shut.  There are easier ways to do this, though.  If you draw 2 dots on a paper, horizontal from each other but not too close to each other, close one eye, stare at one dot, and move closer to the dot you’re staring at, the other dot will disappear. Science.