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Depth Perception Test

Stereoscopic vision and depth perception testing is necessary in identifying diseases such as Amblyopia, Strabismus, Suppression and Stereopsis. Stereovision is how each eye may see an object from different angles, but combines these angles to give us a 3D image. There are many stereoscopic/depth perception tests on the market; some are designed more for children while others to adults. Many of these tests require the patient to identify the “raised” letter, shape or animal to measure depth perception and identify if the patients eyes are working together to identify the intended image. These tests provide intriguing subjects to interest various patients. An Ophthalmology practice should have a variety of these tests on hand if serving patients of varying ages.

 Below simple online test will help you determine whether you have fully functional depth perception (AKA stereoscopic visionbinocular vision3-D vision).

IMPORTANT: This test is not a substitute for a professional examination. If you have any doubts about your depth perception please consult an optometrist.

Step 1: Focus on the circle

Step 1: Focus on the circle

 To perform this test you will use your finger (or thumb) and the green circle below. The  pictures on the left show what it should look like.

To begin, hold your finger in front of the circle, between your eyes and the screen. Focus your eyes on the circle. You should see the circle clearly in the middle between two images of your finger. The finger(s) will appear semi-transparent and slightly blurry.

Note: Some people find this very easy to do, others have to work at it.

Step 2: Focus on your finger

Step 2: Focus on your finger

Next, focus on your finger. The two previous images should merge together into one finger, while the circle splits into two.

Try shifting your focus between the circle and the finger a few times and note how easy or difficult it is.


If you can you see both finger images, you have binocular/stereo vision and both eyes are “switched on”, i.e. working together at the same time.

If you experience any of the following, you may have a depth perception problem:

  • One finger is easier to see than the other
  • One finger is larger than the other
  • Fingers sometimes appear and disappear
  • One finger tends to go directly over the circle while the other finger is far to the left or right.
  • You can only ever see one finger

These symptoms are often caused by one eye being dominant, in which case you may be able to train your other eye to pick up its share of the workload. See your optometrist for more information.


  • If you wear lenses, try the test with and without them.
  • If you can’t “get it”, don’t give up. Most people who initially have problems can learn to control their eyes better with practice.
  • Make it a habit to practice changing focus between close and distant objects. Become aware of what your eye muscles are doing and notice your eyes converging and diverging.

Remember, if you have any concerns please consult an optometrist.

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