Where’s your Blindspot
Actually you have two, one in each eye. Cover your left eye, can you find your blindspot? Let us show you where it is.
We feel this exercise really helps emphasize the importance of eye exams.
1. Sit 18 INCHES away (or at palms distance) from the monitor.
2. Cover your LEFT eye.
3. Focus only at the RED DOT. Eventually you will notice the big face disappear and reappear!
4. Now try it with both eyes open. What happens?
Explanation: You have a blindspot in each of your eyes which is where the Optic Nerve inserts into the eyeball. At this insertion point there are no photoreceptors (cells that ‘see’ the world) and hence we all have a blindspot in each eye. (FYI, the Optic nerve is essentially a wire /nerve that connects the eyes to the brain). When you simply cover an eye, you don’t see a black spot in your vision because your brains masks/blends it into the background.
Implications: Masking blindspots is just one of the many amazing things our brain does that allows us to better function in our world. On the flip side, this also means the brain prevents many people from realizing that have acquired peripheral vision loss… until their eye exam. In a case such as glaucoma, it is the peripheral vision that is lost first. Most glaucoma patients won’t even notice their vision loss until very advanced disease when the central vision (ie. vision used for reading) is affected. Untreated, the disease becomes more difficult to control with the greater likelihood of blindness. This one of many conditions that can be detected during your eye exam and treated to prevent future vision loss/blindness.