What You Need to Know About Depth Perception

2 mins read

Sometimes understanding your eye problems is as simple as knowing what's behind your symptoms. A term you might have heard, but not fully understood, depth perception, offers knowledge of one such problem. Depth perception refers to the measure of your ability to see objects in three dimensions, and judge movement and distance. When you have depth perception issues, it generally links back to other eye problems. Today we'll help you administer an online depth perception test, and explain some of the implications of the results.

Depth Perception Test

Unless your eye doctor has already advised you on the subject, you likely can't be sure if you have depth perception issues or not. So, to begin with, we'll help you administer a quick test using the picture of a tennis ball below.

depth perception test

  1. Hold your extended index finger in front of the image of the tennis ball, roughly centered on the image, with your hand about six inches from your face.
  2. Focus your vision on the tennis ball. If your depth perception works well, you should see two slightly faint, slightly blurred images of your finger on both sides of the tennis ball. You should also be able to make out the complete image of the ball.
  3. Focus your vision, next, on your finger. Again, if the test goes well, you should see tow slightly faint, slightly blurred images of the tennis ball on both sides of your finger.

Follow the steps above, and you'll have preliminary results. Whatever the results of the above test, of course, nothing matches the examination and advice of an eye doctor. If you think you might have serious problems with your depth perception, meet with an eye doctor so they can help you evaluate the seriousness. Either way, now that we have an initial understanding of your depth perception, we can discuss more of the details.

The Elements of Depth Perception

what is depth perception

To have proper depth perception, you need stereopsis, also called binocular stereoscopic vision. Binocular here refers simply to the idea that both of your eyes work consecutively and together to make a unified image. If only one eye comprehends depth properly, it is called monocular. The elements of vision that affect depth perception, as well explained by eyehealthweb.com, include:

  • Known size of an image on the retina: This is simply the eyes habitual memory of objective size.
  • Stereo Vision: This refers to how your brain combines the two images from each eye creates one, unified image that has depth to it.
  • Moving Parallax: Objects at a further distance appear to move much slower than closer.
  • Retinal Disparity: Difference between the visual images that each eye perceives because of the different angles in which each eye views the world; this helps create depth in our world.
  • Fusion: The combined image of both eyes working together.
  • Interposition: Perception of overlapping objects.
  • Linear Perspective: The perceived size change as objects increase or decrease their distance from the eye.
  • Aerial Perspective: The color change eyes perceive at varying distances.
  • Light and Shade: Provides cues on shape and contour of an object.
  • Monocular Parallax: The change in relative perception of speed when you move your head.

The Causes of Depth Perception Issues

 a woman experiencing depth perception issues

Often depth perception issues come in conjunction with other eye problems. Among those are the following:


If you have depth perception issues, you likely also experience blurred vision (as mentioned above). Knowing the causes of blurred vision will help you get to the bottom of your eye troubles. Learn more today about blurred vision and how to respond to it.

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