The blind spot is an area on your retina that has no visual receptors. Because of this, there is a tiny gap in your visual field. While your brain usually fills in the missing information so that you don't notice it, this quick and easy test makes it possible to demonstrate the blind spot.
Start by covering your left eye and looking at the star shape with your right eye. Slowly move forward closer and closer toward your computer screen, all the while looking at the star. At some point, you will notice that the circular dot on the right will disappear. That is because it is in your blind spot! If you move even closer to the screen, the dot will suddenly reappear once it moves out of the blind spot on your retina.
You can also do the same thing with your other eye. This time, cover your right eye and look at the circular dot with your left eye. Move closer to your monitor until the star suddenly disappears.
Be sure to check out our gallery of optical illusions. Learn how they work and what they reveal about the brain.