Depth Perception, What Exactly is It?
- BY Matthew Surrence
Sure, we are all familiar with 3D, especially when it comes to movies and awesome special effects. But have you ever wondered how your eyes are able to see three dimensions on a daily basis? It’s called depth perception – when the brain processes different pictures from each eye and combines them to form a single 3D image so that you can accurately perceive how far away people or objects are from you.
In order to have depth perception, you must have binocular vision, also known as stereopsis. If someone lacks stereopsis, they’re forced to rely on other visual cues to gauge depth. As a result, their depth perception is less accurate.
How to Test Your Depth Perception
There are simple ways to test yourself at home to determine if you have fully functional depth perception. To start, take a look at the below image of a baseball.
Now, hold up one finger, about six inches away from your face, in front of the image. Focus your eyes on the baseball and you’ll begin to see two somewhat transparent images of your finger on either side of the ball.
Next, focus your eyes on your finger. You’ll see two somewhat transparent images of the baseball on either side of your finger. This indicates good depth perception.
Next, test for eye dominance by holding your finger in front of the image of the baseball. Focus on the image and close your left eye. Your finger should appear to the left of the baseball.
Next, open your left eye and close your right eye. Your finger will seem to jump to the right of the baseball. This means that you have functional binocular vision (also known as stereo vision).
Below are signs that you may have faulty depth perception:
- You can see your finger better on one side than the other.
- The view of your finger is larger with one eye than with the other.
- With one eye closed, the image of your finger appears right over the baseball, while with the other one the image of your finger is far to the left or right.
- You can only see one image of your finger.
If you experiences any of these, we recommend that you schedule an eye exam with your eye doctor to see if your vision can be improved.
Common Causes of Depth Perception Problems
A range of conditions can affect your depth perception and cause problems. Some are harmless, while others are more serious, so it’s always good to check with your doctor if you’re experiencing issues.
- Strabismus– a condition where your eyes don’t align properly and point in different directions. It can also cause double vision.
- Blurred vision- blurry vision in one or both of your eyes can alter the image that’s sent to your brain and impair the convergence process. Blurred vision is a common symptom of several eye conditions, such as astigmatism, nearsightedness, farsightedness, and cataracts.
- Amblyopia– commonly called ‘lazy eye,’ this condition is when vision, even when fully corrected with glasses, is reduced in one or both of your eyes. Some common causes of amblyopia are strabismus (see above), refractive errors, and the inability of one eye to focus as well as the other.
- Eye trauma – trauma to the eye, or having one eye, can reduce the quality of your depth perception. Many people with one functioning eye learn to judge depth perception using different signals called monocular cues.
How To Improve Depth Perception
One easy way to improve your depth perception is by wearing prescription glasses. However, if your depth perception is still off even with corrective lenses, you may want to try vision therapy treatments.
There are also exercises that you can practice at home to improve your depth perception. Before setting a plan on your own, we always recommend that you first consult with your optometrist. hey will be able to determine the best way to ensure that your depth perception is functioning to its best ability.