Blind Spot

For a long time, she had tried to convince me the existent of blind spots, but I couldn't believe my mom because she can't prove it, and she usually likes to trick me into believing some interesting "facts" that she makes up.  I'd questioned that is there any real blind spot of our eyes until I saw this amazing image. (blind spot is a part of the field of vision is not perceived) When I closed my left eye and use only my right eye to stir at the little dot on the left side, in a certain distance, I cannot see the big dot on the right side. It disappear in my vision because it's projected on the blind spot of my right eye. It was Edme Mariotte (1620-1684), a Roman Catholic priest, who discovered the blind spot and came up with this testing image.  
I also found a cool website that tests if you really have blind spots!!  http://www.blindspottest.com/