The so-called blind spot is the point in the eye where the retina is interrupted and transitions into the optic nerve. Since there are no photoreceptors at this location, we cannot see at this point in the eye.
However, the brain compensates for this through the visual impression of both eyes—so that we typically do not perceive the blind spot. You can find the blind spot with a simple experiment: Draw two dots on a sheet of paper—12 cm apart and no larger than 1 cm.
Hold the paper at arm’s length and close your left eye. Focus with your right eye on the left dot; you will still see the right dot in your peripheral vision. As you move closer to the paper, the right dot in your peripheral vision will eventually disappear into the blind spot.