A concussion is a mild traumatic brain injury resulting from a blow or jolt to the head, causing the brain to move rapidly within the skull. This sudden movement temporarily disrupts normal neurological function, frequently affecting the visual system. Vision problems following a concussion do not stem from damage to the eye structure, but from the brain’s impaired ability to process and coordinate visual information. The neural pathways connecting the eyes to the brain become less efficient, leading to functional visual complaints.
Common Visual Disturbances After Head Trauma
Post-concussion vision difficulties involve problems with how the eyes and brain work together. One of the most common issues is convergence insufficiency, where the eyes struggle to turn inward to focus on close objects like a book or phone screen. This can lead to eye strain, headaches, and a feeling of words moving on the page during reading.
Many individuals experience photophobia, a hypersensitivity to light that makes normal lighting conditions painful or overwhelming. Blurred vision and double vision (diplopia) are common symptoms, occurring when the brain cannot properly fuse the images received from both eyes. Another functional deficit is saccadic dysfunction, which impairs the rapid, accurate eye movements needed to shift gaze between two targets, making it difficult to smoothly track objects or follow lines of text.
Typical Recovery Timelines
For most people, visual symptoms that arise immediately following a concussion are temporary. The majority of symptoms, such as temporary light sensitivity or mild eye strain, tend to improve within the first one to two weeks with appropriate rest and reduced visual strain. This healing occurs as the brain’s metabolic function stabilizes and neural pathways regain efficiency.
Full visual recovery is usually expected within four weeks of the injury for most mild cases. However, more complex functional issues involving eye teaming or tracking may take longer, sometimes extending up to a few months. If visual complaints persist beyond the one-month mark, they are considered prolonged and are less likely to resolve without targeted intervention.
Factors That Prolong Visual Recovery
Several factors can extend the duration of visual recovery. A history of previous concussions is a key factor, as repeated head injuries compound neurological deficits and slow the recovery of the visual system. Similarly, pre-existing conditions, such as migraines, learning disabilities, or other visual disorders, can lead to longer symptom duration.
Age is another influence; adolescents and older adults often experience slower recovery compared to young adults. The developing brains of adolescents and reduced neuroplasticity in older adults contribute to prolonged visual issues. Furthermore, failure to adhere to initial rest protocols or a delayed diagnosis can prevent the brain from stabilizing, sometimes leading to post-concussion syndrome.
When Vision Problems Require Specialized Treatment
If visual symptoms like double vision, persistent blurriness, or severe difficulty reading continue past the four-week window, specialized medical attention is needed. Worsening vision or the sudden onset of severe dizziness and loss of balance are red flags that warrant immediate evaluation.
Specialized care involves a thorough assessment by professionals such as neuro-optometrists or physical therapists trained in post-concussion visual dysfunction. Unlike standard eye exams that focus on visual acuity, these specialists evaluate how the eyes move, track, and focus together. The primary treatment for chronic post-concussion visual problems is vision therapy, a personalized program of exercises designed to retrain the brain and eyes to work together efficiently, improving eye teaming, focusing flexibility, and visual processing speed.