What is a blind spot?

The place where the optic nerve and retina meet is called blind spot

It is called so because there are no sensory cells at this place(cones and rods)

So we are not able to see anything at this point

Activity to check blind spot

We make a cross mark and round mark on sheet of paper

We concentrate on cross mark and keep bringing sheet of paper closer

Soon we are not able to see round mark

Similarly

 if we do the opposite and concentrate on round mark,we are not able to see crossmark