Are you stereoblind?
Can you see the fern flag?
Stereoblindness is the inability to perceive in three-dimensional (3D) depth using, by combining and comparing images from the two eyes - aslo called stereo vision.
Individuals with only one functioning eye 👀 have this condition by definition, as there is no visual input from the second eye. The condition can also occur when both eyes are healthy but do not function together properly.
Test your stereo vision below. 👇
MPORTANT: This test is not a substitute for a professional examination. If you have any doubts about your depth perception please consult an optometrist.
Can you see the fern flag? 👇
A tip:
Raise your index finger and hold it in front of your face, about as far away as you would have the fern image. Now, look past your finger and focus on something beyond your finger. It helps if it’s something specific, a picture on a wall or something like that.
You will notice your index finger appear to duplicate in your vision. This is how you resolve the fern image, you are simply throwing your focus.
Now, focus on your finger. You will notice the picture on the wall duplicate in your vision. If you continue to switch your focus between your finger and the picture on the wall, you will be performing the very action necessary to quickly resolve the fern image.
A little practice will train you to do this at will, and you will be able to enjoy these images one after another, with minimal effort and delay. It will, incidentally, make those “find the differences in these two images” trivial.
Hope this helps!
What does the world look like to stereoblind people?
It’s really flat! We know this from the handful of people who have learned to use their eyes together as adults — people who are amazed to see their entire world inflate — becoming crisper, clearer and more spacious.
How does being stereoblind affect your life?
When you are a kid, you may have been told that it was no big deal, and that the only consequence was that you would never be a pilot.
This turns out not to be true.
If you do not learn to use your eyes together at a very young age, it affects nearly every aspect of your life:
You develop a more careful and less accurate method for reaching and grasping things than your peers.
You walk differently (with shorter steps, and not looking as far ahead.)
You will probably be considered clumsy and bad at sports.
People who are stereoblind also have lifelong problems deciphering close-together text (e.g. on motorway signs) or picking out objects that are jumbled together — even if they have 20/20 vision.
Stereoblind teens are less likely to get their drivers’ licenses — even if they have no idea that there’s anything wrong with their eyes.