A concussion is a type of traumatic brain injury that occurs when the brain moves or twists inside the skull, often due to a bump, blow, or jolt to the head or body. This movement can cause temporary chemical changes in the brain and interfere with its normal function. A very common symptom following a concussion is light sensitivity, also known as photophobia, affecting approximately 40% of individuals who experience this injury. This symptom can significantly impact daily life, making even normal light levels uncomfortable.
Understanding Light Sensitivity After Concussion
This symptom arises from disruptions in how the brain processes visual information. Specific brain regions, such as the thalamus, which filters incoming visual data and sends signals to other brain areas, can be affected. If the thalamus is damaged or lacks sufficient oxygen and nutrients, it may struggle to filter light effectively, leading to visual overload.
The superior colliculus, a brain region involved in eye movements and spatial orientation, can also be compromised, contributing to light sensitivity. Additionally, a concussion can disrupt the autonomic nervous system, which regulates involuntary bodily functions, including pupil size. This disruption can cause pupils to dilate more than usual, allowing too much light to enter the eyes and exacerbating sensitivity. The brain may also expend extra energy trying to process bright light, which can contribute to overall fatigue.
How Sunglasses Provide Relief
Sunglasses offer relief from concussion-related light sensitivity by reducing the total amount of light entering the eyes. This calms an overstimulated visual system, alleviating discomfort and headaches in bright environments.
Certain types of tinted lenses, beyond just dark shades, can specifically help by filtering out particular wavelengths of light that are often perceived as more irritating. For example, blue light, commonly found in fluorescent lighting and digital screens, can be particularly bothersome for individuals with photophobia. Specialized tinted glasses are designed to block these specific light frequencies, providing targeted relief and making environments more tolerable.
Selecting the Right Sunglasses
When choosing sunglasses for concussion-related light sensitivity, prioritize lenses that offer 100% UVA/UVB protection. While UV protection is always advisable, the primary focus for concussion recovery often shifts to lens tint and type.
Darker lens tints are generally more effective for severe photophobia, as they reduce overall brightness. Additionally, colored lenses, such as those with blue, green, red, or FL-41 tints, have shown promise in mitigating symptoms by filtering specific light wavelengths. Polarization can also be beneficial, as it reduces glare from reflective surfaces like water or roads, which can be particularly irritating for someone experiencing a concussion. Sunglasses with larger frames or wrap-around styles provide more comprehensive coverage, blocking peripheral light and further minimizing visual input.
Guidelines for Sunglass Use During Concussion Recovery
Sunglasses serve as a useful tool for managing light sensitivity during concussion recovery, particularly when outdoors or in brightly lit indoor settings. They provide immediate comfort, helping individuals navigate environments that would otherwise trigger or worsen symptoms. Using sunglasses as needed allows the brain to rest from excessive visual stimulation, supporting the healing process.
However, relying on sunglasses constantly, especially indoors for prolonged periods, can hinder recovery. Over-reliance on darkness can increase light sensitivity over time, potentially prolonging photophobia or creating dependency. It is advisable to find a balance, using sunglasses when necessary for comfort but gradually reintroducing oneself to normal light levels as tolerance improves.
As symptoms diminish, a gradual reduction in sunglass use can help the visual system readjust. Consulting with a healthcare professional, such as a doctor, neurologist, or concussion specialist, is always recommended for personalized advice on managing concussion symptoms, including light sensitivity and appropriate sunglass use. Their guidance ensures the most effective and safe recovery strategy.