Concussion and Your Vision

A concussion is a serious medical condition and should be taken seriously. Concussions occur more often in children because of the sports they play. Concussions can negatively impact vision by causing double-vision, sensitivity to light, and problems with eye tracking.

This article discusses the symptoms of a concussion and how they affect vision,

Close-up of a woman's multi colored eye
Oleksiy Maksymenko / Getty Images


Brain Injury

Nearly three million visits are made to the emergency department every year as a result of some type of traumatic brain injury.

Concussions are head injuries that result from blows to the head. The blow to the head causes the head and brain to move back and forth rapidly and sometimes violently.

This movement is traumatic, possibly causing the brain to bounce around or twist in the skull. This movement can damage brain cells, create chemical changes inside the brain, and even cause all the brain cells to fire at once, much like a seizure.

Another way to describe a concussion is a “bruising of the brain” where function may be affected with no structural damage at all. Even a mild concussion can cause confusion, disorientation, and memory loss.

A blow to the head need not be severe to cause a concussion. Even a mild blow can cause a concussion that could create long-term consequences.

Studies of concussions in high school athletes have shown that even mild concussions can result in serious long-term problems, especially when the athlete is allowed to return to their sport too early or has a history of more than one concussion.

Symptoms

It is important to recognize the signs and symptoms of concussion. The following symptoms may suggest a mild to severe concussion:

  • Headache
  • Blacking out
  • Fatigue
  • Balance problems
  • Disorientation
  • Amnesia
  • Confusion
  • Nausea
  • Vomiting
  • Irritability

Many people mistakenly believe that "blacking out" must occur in order to have a concussion. However, fewer than 10% of sports-related concussions occur with loss of consciousness.

Concussion symptoms can be mild or severe and can last for hours, days, weeks, or even months. After a concussion, the brain could sustain more damage if not allowed to rest.

In the medical and school communities, protocols are being developed to better evaluate children with concussions. These protocols are referred to as “return-to-learn” or “return-to-play” rules.

However, more attention is sometimes placed on “return-to-play” and less on "return-to-learn.” As a result, children with prolonged concussion symptoms report more academic difficulty.

Children often develop vision or eye-related symptoms with concussions.

Many “return-to-learn” protocols do not include a thorough vision examination in the evaluation process despite studies that show eye muscle tasks and convergence (inward turning of the eyes) are affected in many children with concussions.

These issues may not be detected by an MRI or any other tests, but once a person returns to school or work, they realize something is a bit off. The severity of the concussion or multiple concussions can make these visual symptoms worse or longer-lasting.

Concussion and Your Vision

Head trauma and concussions can have major effects on the visual system even when medical imaging shows normal results. The group of symptoms that cause blurred vision, eye coordination issues and dizziness after a concussion is collectively called “post-trauma vision syndrome.”

The main symptoms that occur in post-trauma vision syndrome are:

  • Dizziness
  • Walk or stride (gait) issues
  • Focusing problems
  • Headaches
  • Double vision

It seems that people who have more severe post-trauma vision syndrome symptoms are often people who have some type of previous eye-teaming issues. These people tend to have much more difficulty with reading and eye-tracking after a concussion.

Even mild concussions can affect vision and cause visual dysfunction. Severe concussions can cause blindness and double vision.

More subtle effects on vision are difficulty focusing on near objects or on digital devices (computers, tablets, and smart-phones) after a concussion.

Double Vision

Severe concussions can create true double vision.

Double vision that onsets after a concussion and continues is a sign that more damage may have occurred than originally believed. This should be evaluated immediately to rule out serious injury.

After more serious injury is ruled out, double vision needs to be treated or managed. Double vision is extremely disorienting and can cause:

  • Dizziness
  • Difficulty balancing, walking, and reading
  • Impaired eye-hand coordination

Accommodative Dysfunction

People often struggle to switch their focus from near to far and vice versa. The process of focusing on near objects is called accommodation.

Accommodative dysfunction is similar to presbyopia. Presbyopia occurs around 40 years of age with difficulty focusing on near objects.

Often reading glasses, bifocals or progressive addition lenses are prescribed to remedy accommodative dysfunction.

Teenagers with concussions often have the same experience of loss of near vision. Their eyes may appear healthy, but accommodative dysfunction is often apparent, mimicking presbyopia.

As people age, they lose the ability to focus close up because of changes in the eye's lenses. After a concussion, you might notice this problem because the portion of the brain stem that controls lens focusing may be injured. This localized trauma is almost never apparent on MRI.

Convergence Insufficiency

Another extremely common problem often apparent after a concussion is convergence insufficiency.

Convergence insufficiency is a decreased ability to converge the eyes and maintain binocular vision while focusing on a near target such as reading or working on the computer.

Convergence is the inward turning of the eyes toward the nose to focus on a near object. People who suffer from convergence insufficiency have difficulty using their eyes together and often complain of tired, achy eyes when reading.

Sensitivity to Light

People often complain of sensitivity to light and glare. In fact, after a headache, light sensitivity is the second most common symptom seen after a concussion.

It is thought to be a result of the brain’s inability to adjust to various levels of brightness after an injury. This light sensitivity can create difficulty holding focus for any length of time.

Eye Tracking

Small, quick eye movements sometimes occur after a concussion that can cause eye-tracking problems.

These eye movements can also cause problems with eye-hand coordination, sometimes resulting in problems during sports and in the classroom. This is usually referred to as an ocular-motor dysfunction.

Delayed Visual Processing

Some people with concussions experience prolonged visual processing speed. Often tough on an athlete, a delay in processing images results in difficulty reading the field, judging distances, judging the speed of other players, and the speed of a ball.

Concussions Doctor Discussion Guide

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A Word From Verywell

Most of the issues that often occur as the result of a concussion will resolve, but only with rest. Doctors often recommend total rest with no brain stimulation, including no video games, TV, or socializing with friends. The fewer stimuli the better. This gives the brain a chance to recover.

If symptoms persist, re-evaluation by a neurologist will be recommended to rule out serious and sometimes life-threatening medical problems.

Many of the vision conditions respond well to vision therapy. Vision therapy, most often performed by behavioral optometrists, consists of eye exercises and training that help retrain the eye muscles and reaction time. 

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Troy Bedinghaus, OD
Troy L. Bedinghaus, OD, board-certified optometric physician, owns Lakewood Family Eye Care in Florida. He is an active member of the American Optometric Association.