Blind spot
Blind spot: Cover your left eye, and with your right, focus intently on the cross. Slowly move move your head back and forth toward the computer until the circle disappears. At this point, light rays from the circle are focused on the retinal artery where there are no rods or cones.
Blind spot: Cover your right eye, and with your left, focus intently on the cross. Slowly move move your head back and forth toward the computer until the circle disappears. At this point, light rays from the circle are focused on the retinal artery where there are no rods or cones.