Concussion and Your Vision

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Concussion is a common, yet often misunderstood diagnosis. Did you know that a concussion is actually termed a traumatic brain injury? A concussion is a serious medical condition and should be taken seriously. Concussions occur more often in children because of the sports they are involved in. Concussions among children and teenagers are beginning to be taken more seriously by school coaches and medical staff due to the long-term ramifications that may occur.

Nearly five million concussions occur every year, making the condition the most common type of traumatic brain injury. Concussions are simply 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 to the brain tissue and can cause the brain to bounce around or twist in the skull. This movement can damage brain cells and create chemical changes inside the brain. It can 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.

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 develop a concussion. However, fewer than 10 percent 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 that suffer 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. 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, and 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 issues and eye tracking problems 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.

The following eye or vision symptoms can occur 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. Eye-hand coordination can also be impaired.
  • 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 the problem. 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 we age, humans lose the ability to focus at near because of changes in the lenses of the eyes. After a concussion, one may lose this ability because the portion of the brain stem that controls focusing of the lens may be injured by the trauma. Unfortunately, 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 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.

A Word From Verywell

Fortunately, 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 video games, TV, or socializing with friends. The less stimuli the better. This gives the brain a chance to recover. If these conditions persist, re-evaluation by a neurologist will be recommended to rule out serious and sometimes life threatening medical problems. Most of these problems are treatable if they do not resolve on their own. 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. 

Source:

Wolter, M, Pelino, C, Pizzimenti, J, Concussion and chronic traumatic encephalopathy, Review of Optometry, March 15, 2017.

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