Binocular Vision

With well-functioning binocular vision, the brain is able to determine depth and speed of objects.

Last Updated: March 11, 2023

What is binocular vision?

What we see is the result of signals sent from the eyes to the brain. Usually the brain receives signals from both (bi) eyes (ocular) at the same time. The information contained in the signal from each eye is slightly different and with well-functioning binocular vision, the brain is able to use these differences to judge distances and coordinate eye movements.

What causes loss of binocular vision?

Binocular vision anomalies are among the most common visual disorders. They are usually associated with symptoms such as headaches, eye strain, eye pain, blurred vision, and occasionally double vision. There are many reasons binocular vision might become reduced or lost altogether, including:

  • Reduced vision in one eye
  • Loss of coordination of movement between the two eyes (strabismus)
  • Problems with the brain comparing images from both eyes

Why is this important?

One of the main benefits of binocular vision is the ability to judge depth and speed of objects. Children with poor or no binocular vision can have difficulty with these tasks. This may lead to problems with:

  • Pouring liquids into a cup
  • Catching or hitting fast moving balls
  • Judging how quickly a car is approaching while crossing roads
  • Walking up or down stairs

You can experience binocular vision by closing one eye and trying to pour water into a glass or bring two pencil tips together to touch. It is more difficult to perform these tasks with one eye closed than with both eyes open, because your skill in judging depth is poorer using just one eye. 


Hamed M., Goss DA., Marzieh E. (2013). "The relationship between binocular vision symptoms and near point of convergence.” Indian Journal of Ophthalmology. 61(7):325–328. doi:10.4103/0301-4738.97553.


Related Articles

Strabismus (crossed eyes)

Read more