Because no photoreceptors are found in the area where the optic nerve is attached to the retina, this area is called the blind spot. To locate your blind spot, look at the symbols below. Center and hold this page about 50cm in front of your eyes so that the + is on your left. Close your right eye and focus your left eye on the ∙. Slowly move the page toward your eyes while looking at the ∙.
Does the cross disappear? This is known as the blind spot.
Using a ruler, have your partner measure the distance between your eyes and the page. At what distance from your eyes do you reach your blind spot?
Continue to move the page toward you. What happens to the cross?
Repeat the process using your right eye and focusing on the cross. Does the circle disappear>
At what distance from your eyes do your reach your blind spot in your right eye?
What happens to the circle as your continue to move the page towards you?
Dominant Eye Determination
Most individuals do not make use of both eyes. They depend more heavily on one eye – the dominant eye.
Roll a sheet of paper into a tube approximately 4cm in diameter.
Hold the tube at arm’s length. Look through it with both eyes at some object across the room.
With the tube held steady, close one eye then the other. Which eye still sees the object through the tube? This is your dominant eye. Is it on the same side as your dominant hand?
Near Point of Vision
The distance from the eye to the nearest object that can be focused clearly is called the near point of vision.
Place one hand over an eye and focus on a pen held at arm’s length.