Concussions, a form of mild traumatic brain injury, arise from a sudden jolt or blow to the head or body that causes the brain to move rapidly within the skull. This forceful movement can lead to temporary changes in brain function. Eye-related symptoms are frequently observed indicators that warrant attention, providing clues about the brain’s temporary disruption.
Observable Eye Signs
Concussions can lead to several observable eye signs, providing important clues about the injury. These signs often involve irregularities in pupil response, difficulties with eye movements, and various visual disturbances. Recognizing these changes can help in identifying a potential concussion.
Pupil irregularities are a notable indicator following a head injury. Pupils may appear unequal in size (anisocoria), react slowly or not at all to changes in light, or appear abnormally dilated. These changes can signal disruption in the brain areas that regulate pupil size and response.
An individual might struggle with smooth pursuit, which is the ability to track a moving object. Their eyes may move in a jerky or uncoordinated manner. Nystagmus, characterized by rapid, involuntary eye movements—either side-to-side, up-and-down, or circular—can also occur. The eyes might not move together in a coordinated way, leading to misalignment or issues with eye teaming.
Blurry vision is a common complaint. Double vision, or diplopia, arises when the eyes cannot work together to create a single image. Sensitivity to light, known as photophobia, is a widespread symptom, where even moderate lighting can cause discomfort. Some individuals may also report seeing “stars” or flashes of light.
Difficulty focusing, particularly on near objects, is often experienced. This can manifest as eye strain, fatigue, or problems with reading comprehension. Activities requiring sustained visual concentration, such as reading or using a computer, can become tiring or induce headaches more easily. This struggle to maintain clear focus is often linked to accommodative insufficiency, where the eye’s ability to adjust focus is impaired.
How Concussion Affects Vision
A concussion impacts vision by temporarily disrupting the complex communication pathways between the eyes and the brain. Over half of the brain’s neural network is dedicated to processing visual information, making the visual system particularly susceptible to head trauma. The forceful movement of the brain during a concussion can stretch and damage brain cells and nerve pathways.
This disruption affects the brain’s ability to coordinate eye movements and process visual input effectively. Areas of the brain responsible for visual processing, balance, and eye-brain coordination can be temporarily impaired. Consequently, the brain may struggle to integrate images from both eyes, leading to symptoms like double vision or difficulty tracking objects.
The brain’s control over pupil response can also be affected. Damage or disruption to the brainstem, which helps regulate pupil size, can result in dilated pupils or pupils of unequal size that react slowly to light. The temporary chemical changes within the brain following a concussion contribute to these visual processing difficulties. These impairments are not typically due to direct damage to the eyes themselves but rather a communication problem between the brain and the eyes.
When to Seek Professional Help
Observing any eye signs or other symptoms after a head injury warrants immediate medical attention. While some concussion symptoms may seem minor, self-diagnosis is not sufficient. A trained healthcare professional is necessary for proper diagnosis and management of a concussion.
Delaying assessment can prolong recovery and potentially lead to more serious complications. Early detection and appropriate intervention have been shown to significantly reduce recovery time. Healthcare providers can conduct thorough physical and neurological examinations, including specific concussion tests, to evaluate symptoms and brain function.
It is important to seek emergency care if symptoms worsen or new ones appear, such as a severe, worsening headache, seizures, repeated vomiting, or severe confusion. Even if symptoms are subtle or do not appear immediately, a medical evaluation is recommended. Prompt assessment helps rule out more serious injuries and ensures a tailored recovery plan.