Menu

What to Know About Depth Perception

Medically Reviewed by Dan Brennan, MD on June 15, 2021

Your eyesight allows you to focus on things near and far as you look around each day. Your brain and eyes work together to make out how far away something is. When you look at something far away, your eyes focus differently than when you look at something up close.

Your eyesight depth perception is how images appear three-dimensional (3-D).

Understanding Your Eyesight

Your eye is made up of different parts that all work together to help you see. Your vision is an image that your brain projects from the information it receives from these parts.

The first step in this process is that light passes through your cornea, which is the front layer of your eye. Your cornea is slightly rounded so that light bends when it enters your eye, allowing for better focus.

The light enters your eye through the dark circle in the center called your pupil. The colored part of your eye — the iris — allows your pupil to grow bigger or smaller to let in more or less light.

After that, light moves through the inner part of your eye called the lens. Your lens and cornea work together to focus light and give a clear image to the retina at the back of your eye.‌

Special cells in your retina are called photoreceptors, They turn the received light into electrical signals that pass through your optic nerve to your brain. Your brain then turns the messages received into images.

How Depth Perception Works

When it comes to your eyesight, depth perception is your ability to see things three-dimensionally. You’re able to distinguish the length, width, and depth of objects as well as estimate how far they are from you.‌‌

For the most accurate depth perception, you need binocular vision. This means both eyes focus on a single object at the same time. You may notice that if you close one eye or the other things around you look slightly different. That’s because when you use both eyes, your brain merges the two images to create a three-dimensional view.‌

This brain-eye process is called convergence because your eyes each look at objects from slightly different angles. The resulting image your brain successfully makes is called stereopsis.‌

If you only have a single eye or have an eye with impact vision, your depth perception may not be strong. This is especially true when you first begin to rely on a single eye for vision as your brain adjusts. Over time you may find that your depth perception becomes more accurate because your brain learns how to process monocular (single eye) vision.

Reasons that you may have inaccurate depth perception include:

  • Blurry vision in one or both of your eyes
  • Strabismus, or crossed eyes
  • Amblyopia, or lazy eye
  • Nerve problems in one of your eyes‌
  • Trauma to one of your eyes‌‌

If you find yourself squinting or tilting your head to see objects clearly, contact your eye doctor for help. They can do an eye exam to find out the cause of your concerns. When it comes to your vision, it’s important to seek treatment early on so problems can be addressed before they get worse.

Vision Problems Affecting Depth Perception

Blurred vision. This is also known as refractive errors. You may have blurry vision for a number of reasons. Nearsightedness causes things far away to appear blurry, and farsightedness causes things closer to you to appear blurry. These eye conditions can affect you regardless of your age or sex.‌

If you are 40 years old or older, you may struggle to read things up close. This is a different condition called presbyopia. It is very common and affects one in three people who are 40 years old or older.

If your cornea is misshapen, it cannot work with your lens to focus light properly to the back of your eye. This condition is called astigmatism. You may need glasses or contacts to help you see more clearly as this can also blur your vision.

Strabismus. For most people, your eyes look straight ahead and move together to look at the world around you. However, if one or both of your eyes point in another direction, it is called strabismus. Individual conditions that fall under this category include:

  • Esotropia, which is when one or both of your eyes turn in toward your nose
  • Exotropia, which is when one or both of your eyes turn out away from your nose 
  • Hypertropia, which is when one or both of your eyes turn upward
  • Hypotropia, which is when one or both of your eyes turn downward

If you find out you have one of these conditions early on and get treatment, your eyesight can be corrected. If left untreated, these conditions may lead to a lazy eye that doesn’t focus. Lazy eye happens when your brain and eyes don't work together properly to produce accurate images.‌

If you see changes in your eyes or find yourself squinting or tilting your head to see objects clearly, contact your eye doctor for help. They can do an eye exam to find out the cause of your concerns. When it comes to your vision, it’s important to seek treatment early on so problems can be addressed before they get worse.

Show Sources

SOURCES:

American Academy of Ophthalmology: “Depth Perception.”

Journal of Cognitive Research: Principles and Implications: “Magnitude, precision, and realism of depth perception in stereoscopic vision.”

National Eye Institute: “How the Eyes Work.”

New York State Department of Health: “Types of Vision Problems.‌

© 2020 WebMD, LLC. All rights reserved. View privacy policy and trust info