Lesson 17 – Experiment: Find Your Blind Spot

You may think your vision is good, but did you know you have a blind spot? That is a place where you cannot see anything. Normally you do not notice your blind spot. Here is an experiment to help you find it.

1. Close your right eye and have the screen at arm’s length away. Or, print this page and hold it at arm’s length.
   
   
2. Look at the dot with your left eye. You should also be able to see the plus sign.
   
   
3. Slowly move closer to the screen (or move the page slowly toward you). The plus sign will disappear at a certain point.
   
   

You can test your right eye by closing your left eye. Then focus on the plus sign.

What is happening? Blood vessels and a major nerve pass through a place at the back of your eyeball. Millions of cells in your eyes receive images and send information to your brain. But there are no cells at that particular place, so you have a blind spot.