While a concussion is a traumatic brain injury, the eyes are often the primary window through which post-concussion vision issues manifest to the patient. It is common for individuals in Toronto and the Greater Toronto Area to assume that if their eyes are physically healthy, their vision is fine; however, the complex visual system involves more than just the eyes. A concussion disrupts the neural connections between the brain and the visual processing centers, leading to persistent blurred vision and other visual symptoms that can significantly impede daily life. Recovery from these visual dysfunctions often requires a multidisciplinary approach involving both an Optometrist and a physical rehabilitation team to address the root of the functional vision impairment. 

What are the signs and symptoms of a concussion?

Symptoms of a concussion do not always appear instantly; some take hours or days to surface as the chemical changes in brain cells evolve. While many patients expect immediate unconsciousness, most mild traumatic brain injuries do not involve a loss of consciousness but rather a constellation of physical indicators¹. These often include persistent headaches, nausea, dizziness, and a heightened sensitivity to light known as photophobia. Patients may also experience cognitive and emotional shifts, such as brain fog, increased irritability, and a general sensation of feeling slowed down. 

Among the most critical visual red flags are blurred vision, double vision (diplopia), and significant difficulty tracking moving objects. These post-concussion visual symptoms are signs that the oculomotor control centres in the brain are struggling to coordinate the eyes². When the visual pathways are disrupted, the brain must work much harder to process information, leading to rapid fatigue and a decline in visual attention and visual memory. 

How to check pupils for concussion

Medical professionals check for anisocoria, which is an uneven pupil size, or a sluggish reaction to light, to determine if there is significant pressure or damage to the cranial nerves¹. This assessment is a standard part of evaluating the autonomic visual system following a brain injury. If one pupil remains dilated while the other constricts, it indicates a medical emergency that requires immediate intervention from an Ophthalmologist or emergency physician. 

It is important to emphasize that while checking pupils at home is a common practice for concerned family members, it is not a substitute for a clinical assessment by a qualified Optometrist. A normal-looking pupil does not mean a concussion hasn't occurred, as many visual disruptions happen within the internal visual processing centers rather than the physical structure of the eye itself. Relying solely on pupil size can lead to a missed diagnosis of post-concussion syndrome or other lingering visual disorders. 

Why do I have blurry vision after a concussion?

Blurry vision occurs because vision is a complex process involving several areas of the brain that can be knocked out of sync by the physical impact of a traumatic brain injury. The brain must coordinate the mechanical movement of the eyes with the sensory input it receives to create a clear image. When this synchronization is lost, the patient experiences post-traumatic vision syndrome, where the visual system can no longer maintain a single, sharp focus². 

One common cause is accommodation issues, where the eyes struggle to change focus between near and far objects quickly. This is often accompanied by convergence insufficiency³, a condition where the eyes have trouble turning inward to focus on close tasks like reading or using a smartphone. Furthermore, binocular vision dysfunction may occur, meaning the brain has trouble coordinating both eyes to work together as a single team. This lack of oculomotor control leads to depth perception issues and a general feeling of being visually overwhelmed in busy environments. 

The importance of a concussion eye exam

A standard vision test measuring visual acuity on a wall chart is not enough to diagnose post-concussion vision syndrome because it only measures how well one sees at a distance. An eye exam at Kodak Lens Vision Centres goes much deeper, evaluating how the eyes move, work together, and focus on dynamic targets⁴. Optometrists look for oculomotor dysfunction, specifically testing smooth pursuit (the ability to follow a moving object) and saccades (the ability to jump focus between two points). 

During these exams, a developmental optometrist or an Optometrist specializing in neuro-optometric rehabilitation can identify specific visual skill areas that have been weakened. They may recommend specialized lenses to alleviate symptoms and support the recovery of the visual system. For instance, Kodak Lenses with blue light filtering can help manage light sensitivity, while prism lenses may be utilized to shift the visual field and reduce the strain caused by binocular vision issues. These tools provide immediate relief while the patient undergoes more intensive rehabilitation⁴. 

Moving beyond the eyes: Concussion treatment

Recovery from a concussion rarely happens in a vacuum; it requires a multidisciplinary approach that addresses the vestibular and cervical systems alongside the eyes. Because the visual, balance, and neck systems are deeply intertwined, a dysfunction in one often affects the others. In Toronto and the Greater Toronto Area, the modern philosophy of treatment has shifted toward active recovery, which involves performing controlled activities that do not trigger a severe spike in symptoms. 

This approach focuses on staying just below the sub-symptom threshold, allowing the brain cells to heal without being overstressed. A rehabilitation team often consists of an Optometrist, a Physiotherapist, and sometimes a Chiropractor to ensure every aspect of the injury is addressed. By treating the whole person, patients can see faster improvements in their visual cognition and overall stability. 

How concussion physiotherapy helps

Vestibular rehabilitation uses specific exercises to recalibrate the inner ear and eyes, which is essential for reducing dizziness and visual motion processing issues. When the vestibular system and the visual system are not communicating correctly, the patient may feel like the world is moving when they are standing still. Physiotherapy also incorporates sensorimotor training to improve the communication between the neck muscles and the brain, which is vital for maintaining steady oculomotor control. Balance training is another cornerstone of this therapy, helping patients regain stability to prevent secondary falls or further injuries. 

The role of chiropractic care in recovery

Many concussion symptoms actually stem from the whiplash effect on the upper spine, leading to what are known as cervicogenic headaches. Chiropractic care can help manage the nervous system regulation by addressing the physical tension and misalignment caused by the initial impact. Gentle adjustments may help the body transition out of the fight or flight state that often accompanies head trauma. In professional environments like Circle Care, practitioners work together on a single recovery plan, ensuring that the manual therapy provided by a Chiropractor supports the vision therapy exercises prescribed by the Optometrist. 

Lifestyle tips for managing visual strain

Effective screen hygiene is paramount for recovery, which includes reducing high energy blue light exposure and taking frequent breaks to prevent visual fatigue. The brain requires significantly more energy to process digital information after an injury, so limiting screen time helps preserve cognitive resources. Environment tweaks, such as using green light therapy or dimming overhead fluorescents, can also be beneficial, as these light sources can be noisy for a recovering brain. 

Proper hydration and nutrition support long-term brain health and the maintenance of the vitreous and neurological pathways. Omega-3 fatty acids are particularly noted for their role in supporting brain cell repair. Maintaining a consistent intake of water ensures that the visual system functions at its peak capacity during the demanding process of neuro-optometric rehabilitation. 

When should I seek emergency care for blurry vision?

While many vision issues can be managed through scheduled appointments at Kodak Lens Vision Centres, certain red flags require immediate medical attention¹: 

• One pupil is significantly larger than the other or does not react to light. 

• The patient experiences extreme drowsiness or an inability to wake up. 

• A headache that gets progressively worse and does not go away with rest. 

• Repeated vomiting, seizures, or a sudden loss of visual field. 

Blurry vision after a concussion is a treatable condition, but it often requires professional intervention to resolve fully. If you are experiencing persistent double vision, difficulty focusing, or general visual discomfort, booking a comprehensive assessment with an Optometrist and a physical rehabilitation specialist is the most effective way to ensure a complete recovery. 

References

¹ 2024, Concussion Symptoms and Causes, Mayo Clinic:https://www.mayoclinic.org/diseases-conditions/concussion/symptoms-causes/syc-20355594

² 2023, Traumatic Brain Injury and Vision, American Academy of Ophthalmology:https://www.aao.org/eye-health/diseases/traumatic-brain-injury-vision

³ 2025, Convergence Insufficiency, National Eye Institute:https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/convergence-insufficiency

⁴ 2024, What is Neuro-Optometric Rehabilitation?, Neuro-Optometric Rehabilitation Association:https://noravisionrehab.org/patients-caregivers/about-neuro-optometric-rehabilitation

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