A concussion is a mild traumatic brain injury (mTBI) resulting from a bump, blow, or jolt to the head, or from a force to the body that causes the brain to move rapidly within the skull. This sudden movement can temporarily disrupt normal brain function, leading to a range of symptoms. Blurry vision is a common symptom experienced after a concussion, indicating the brain’s temporary struggle to process visual information effectively.
The Visual Impact of Concussions
Blurry vision after a concussion does not typically stem from direct damage to the eye itself. Instead, it arises from the temporary disruption of the brain’s ability to process visual information and coordinate eye movements. The neural pathways that control how the eyes focus, team together, and track objects can be affected. This can lead to issues with the accommodative system, which controls the eye’s ability to adjust focus for various distances, and the vergence system, responsible for the eyes working together to maintain a clear single image.
When these systems are disrupted, tasks like reading, using digital screens, or following moving objects can become challenging. The brain’s visual processing centers, which interpret signals from the eyes, may also be temporarily impaired. This can result in symptoms such as difficulty focusing, eye strain, and sensitivity to light.
How Long Blurry Vision Typically Lasts
The duration of blurry vision following a concussion can vary considerably. For many people, blurry vision resolves within days to a few weeks after the injury. However, some may experience persistent blurry vision for a longer period.
Several factors can influence this recovery timeline. The severity of the concussion plays a role, as more severe injuries may lead to prolonged symptoms. Individual differences in brain healing, age, and overall health can also affect how quickly symptoms subside. Furthermore, pre-existing conditions like migraines or other vision disorders might extend the duration of blurry vision. Previous concussions can also affect recovery.
When Blurry Vision Becomes a Concern
While blurry vision is a common concussion symptom, certain signs indicate a more serious issue or prolonged recovery. Immediate medical attention is necessary if blurry vision worsens significantly, if there is any vision loss, or if it accompanies other concerning symptoms. These red flags include a severe or worsening headache, repeated vomiting, confusion, seizures, or weakness or numbness in the arms or legs. Changes in pupil size or slurred speech also warrant urgent evaluation.
If blurry vision persists beyond a few weeks, or if it is not gradually improving, it may indicate a more complex recovery or even the development of post-concussion syndrome (PCS). PCS involves a cluster of symptoms that continue for months, and vision problems can be a part of this. In such cases, specialized evaluation by a healthcare provider experienced in concussion management, such as a neuro-optometrist, may be beneficial to address the visual difficulties.
Supporting Visual Recovery
Supporting visual recovery after a concussion involves allowing the brain to heal and gradually reintroducing visual demands. Rest involves limiting activities that strain the eyes, such as excessive screen time, reading, or watching television, especially in the initial days. Gradually returning to visual activities as symptoms improve is advised.
Modifying the environment can also help manage visual discomfort. This might involve dimming lights, using anti-glare filters on electronic devices, and increasing font sizes when reading. Wearing polarized sunglasses outdoors can reduce light sensitivity.
While some eye exercises might be suggested by a healthcare professional to improve focus and coordination, it is important to consult with them before starting any specific visual therapy.