Light Sensitivity After a Brain Injury

Dr. Russel Lazarus, July 25, 2021

According to Optometry and Vision Science, over 40% of people with a brain injury are sensitive to light. 

People who have experienced a concussion may become sensitive to light, a condition known as photophobia, days, weeks or even months after their traumatic brain injury.

Eye doctors with a special interest in neuro-optometry can help.

What is photophobia?

Photophobia is a strong dislike of light.

Where most people might find the level of light to be comfortable, those with photophobia will experience discomfort, even pain, headaches or migraines.

This is especially true if they’ve had concussion or post-concussion syndrome (PCS) symptoms such as blurry vision, double vision or eye strain.

Fortunately, concussion-related photophobia and other TBI symptoms can typically be alleviated with neuro-optometric rehabilitation.

Symptoms of light sensitivity

While light sensitivity is a common problem following a head injury, the symptoms can be difficult to distinguish because they frequently coincide with other brain injury symptoms.

The most common symptoms of post-concussion light sensitivity include:

  • Discomfort from interior lighting
  • Computer screens cause sore eyes
  • Ocular pain
  • Fatigue
  • Eye strain
  • Headaches or migraines
  • Inability to tolerate bright light

Additional post-concussion symptoms may include:

  • Cognitive fatigue
  • Difficulty multitasking
  • Vertigo or dizziness

While light sensitivity isn’t always the source of these symptoms, they may occur concurrently. Furthermore, following a brain injury, your brain may expend extra energy processing intense light, leaving less energy for other functions.

If you’ve experienced any of the above symptoms after a concussion, contact an eye doctor near you.

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Causes of light sensitivity after head injury

When it comes to TBIs, photophobia is caused by injury to the thalamus, a structure in the brain that filters incoming visual information and delivers neural signals to various sections of the brain.

The arteries that carry oxygen to the thalamus can become damaged after a head injury, preventing it from receiving necessary oxygen and nutrients.

If the thalamus is not filtering incoming light effectively, then your brain may become overloaded with too much visual information. Many concussion patients prefer dark settings with less visual stimulation for this reason.

However, light sensitivity isn’t always caused by thalamic injury, photophobia can also result from damage to these areas:

Autonomic nervous system (ANS)

The autonomic nervous system (ANS) controls the majority of your body’s autonomic functions, including blood pressure, respiration, heart rate, pupil dilation, and more.

Your pupils may dilate more than usual if your ANS is disrupted, allowing  too much light to enter the eye and causing light sensitivity.

Superior colliculus

The superior colliculus is a portion of the brain that controls your eye muscles and keeps you orientated in space. If this part of the brain malfunctions a person’s vision may become unstable.

Vestibular system

The brain uses three systems to help people detect and understand where they are in relation to the things around them: the inner ear vestibular system (balance), propriocepter system (touch), and the visual system (sight).

If the vestibular system has been damaged in a brain injury, there is a high chance that the brain will receive conflicting signals from the vestibular and visual systems. As a result of this, the brain enhances the signals from the visual system leading to light sensitivity and photophobia.

Following a brain injury, a person is likely to experience a combination of various symptoms, which are treatable.

Neuro-optometric rehabilitation can help

Patients with visual deficiencies due to physical disability or traumatic brain injuries can benefit from neuro-optometric rehabilitation.

The goal of neuro-optometric rehab is to reteach the brain so that patients can continue to enjoy their lifestyles, even enjoy simple pleasures such as reading, watching sports, going to the movies and driving.

Many functions of the visual system, such as how the eyes work together, are evaluated by a neuro-optometric rehabilitation optometrist. Various filters and prisms, as well as visual exercises to enhance the eye-brain connection, may be used as treatment options.

Schedule a functional vision evaluation with an eye doctor near you to see if neuro-optometric rehabilitation can change your life.