How Do Brain Injuries Affect Vision?

Traumatic brain injuries (TBIs) are those injuries caused by incidents in an uncontrolled environment that alter the ability of the brain to carry out its functions. Non-traumatic brain injuries are those that affect the brain in a controlled environment, in such cases as a stroke, infection, or tumor.

Those affected by traumatic and non-traumatic brain injury may notice blurry or distorted vision, or may have trouble with neural pathway connection that can lead to poor coordination between the brain and the eyes. Conditions such as blurred vision, double vision, decreased peripheral vision, and loss of vision in one or both eyes may follow after a brain and head injury.

What Happens to Vision after a Brain Injury

After a brain injury, your brain’s general spatial orientation may begin to break down. Spatial orientation allows you to understand where you are in space as you sit, stand, walk, run, ride, or drive.

The system that allows you to orientate is driven by two modes of vision:

1. Focal vision mode – This vision mode relies almost solely on the eyes’ input and the brain’s response to what objects are that you see. It is sometimes called central vision.
2. Ambient vision mode – This vision mode relies on your peripheral vision as well as your brain’s interpretation of where objects that you see are located. It helps you locate yourself in space.

Brain and head injuries tend to cause vision problems in ambient vision mode, which means you can still recognize what objects are without the ability to properly locate them in space. Everyday tasks rely heavily on the efficacy of the ambient vision process, and they become more difficult as that process breaks down.

Tasks that involve high stimulation, such as shopping or driving, may become impossible. The overwhelming number of objects to process in space can overload a damaged brain, which will be unable to conclude what movement or action is safe to complete a given task.

Compromised vision processes lead to additional post-brain injury vision problems that can affect everyday life.

Vision Problems Resulting from Traumatic and Non-Traumatic Brain Injury

In response to disability, your brain will try to adapt to your condition. In doing so, it is likely to decrease its ability to perform other functions in favor of trying to perform large-scale functions. This may lead to such post-brain injury vision problems as:

• Poor tracking – inability to locate objects in space disables the ability to do so continuously; difficulty reading
• Loss of focus – your brain may try to shift your focus constantly to find objects spatially
• Misalignment – eyes may change alignment to better suit compromised vision
• Double-vision – a slight misalignment causes images to misalign, as well
• Problems gaze-shifting – loss of focus makes moving quickly between focal areas challenging
• Blurred vision – inability to piece together whole information causes blurring of visual input
• Compromised depth perception and peripheral vision – gaze-shifting issues interfere with the ability to judge distance, and can interfere with driving, walking, and overall safety
• Balance and posture problems – subconscious changes in body response result from poor vision
• Spatial disorientation – inability to place surrounding objects in space causes problems with placing oneself in space
• Light sensitivity and headaches – noticeable physical changes that result as a result of poor accommodation (eye focusing) skills

Affected individuals may also experience egocentric shifts in which the ambient vision process tries, but fails, to provide information about the surrounding environment. It causes a conscious change in posture or locomotion to compensate for confused visual input, such as the perception that the ground or floor is tilted.

In combination with additional treatments, vision therapy can help correct some of the causes of vision problems stemming from traumatic and non-traumatic brain injury. Patients most often find success by addressing each visual problem individually with vision therapy exercise and expert care with 100% effort on a consistent basis. Get in touch with the team at OCVT today to find out more about vision therapy and how it can help the brain injury recovery process.