How Concussions Affect Vision

       More and more people in our society are becoming aware of the severity of concussions and the effects they can have on one’s life. But not everyone realizes that these effects oftentimes manifest as functional vision disorders. According to The Concussion Project, over 50% of patients with a concussion or post-concussion syndrome have visual problems. Up to 1/3 of concussion symptoms are visual, proving just how intimately related the brain and visual system are. A concussion can occur from a direct or indirect blow to the head, causing the brain to hit the inside of the skull. The Concussion Project claims that nearly 4 million concussions occur every year in the US alone.

Common symptoms of a concussion can include:

·         Dizziness

·         Double vision

·         Eye strain

·         Headaches during visual tasks

·         Poor reading comprehension

·         Head tilting

·         Problems with balance

·         Poor depth perception

·         Sensitivity to light

·         Aching eyes

·         Loss of visual field

·         Blurred vision

·         Ocular motor dysfunction

·         Motion sensitivity

·         Reduced cognitive abilities

·         Reduced visual processing speed

·         Convergence insufficiency

·         Accommodative insufficiency

       Contrary to popular belief, most concussions actually do not include a loss of consciousness. The Advanced Vision Therapy Center states that fewer than 10% of sports-related concussions have associated loss of consciousness. Not surprisingly, sports are the most common cause of concussions in children. Since loss of consciousness is not a required component, oftentimes people (children especially) do not even know that they have one. This makes it increasingly difficult to recognize and diagnose.  Another challenging aspect to diagnosing and treating concussions is that the subsequent vision problems are not always immediately obvious. Visual symptoms can take up to several weeks to surface.

       The Advanced Vision Therapy Center states that 67% of the neural connections within the brain are involved with some aspect of vision, including visual input, visual perception, and visual integration. Some visual symptoms following a concussion can be simply treated by lenses or prisms. But vision therapy is a form of neuro-optometric rehabilitation and thus the best choice of action following a head injury. Vision therapy is sometimes most effective after the brain has had a little time to heal.

        The most common visual disorders that are associated with concussions mentioned in the symptoms above include convergence insufficiency, which is the inability of the eyes to turn inward enough to focus on a close target. This contributes to double vision, eye strain, headaches, and so on. Another common disorder is accomodative insufficiency, which is the inability to successfully change your focus from near to far and vice versa. This contributes to blurred vision, aching eyes, and more. Reduced visual processing speed and ability is also possible, which is difficulty in your brain’s ability to quickly make sense of visual information. Poor reading comprehension is often a result of a reduced visual processing ability. Ocular motor dysfunction is also possible following a concussion, which is a defect in the ability to have purposeful eye movement. This can be exhibited in a variety of symptoms, all which are easily treatable by vision therapy!

       If you are experiencing vision problems due to a concussion, head injury, or seemingly out of the blue, then schedule an appointment with a developmental optometrist to receive a comprehensive vision evaluation.

-Emily Thompson, Vision Therapist