What is Neuro-Visual Rehabilitation and
How Does It Help Patients with Brain Injuries
Neuro-Visual Rehabilitation is also referred to as Vision Therapy, a specialty in Optometry.
When we consider vision, we should really be thinking about more than just visual acuity (which is vision clarity or sharpness). Vision is not just seeing a precise image, but also being able to derive meaning from whatever it is that we see. This part of vision is something that is very complex, and it requires several skills. According to some researchers, between 80 and 85 percent of our cognitive activities, learning and perception are influenced by our vision.
When someone suffers from a neurological impairment – for example through a stroke, concussion or traumatic brain injury, getting back that visual acuity can be difficult. Neuro-visual rehabilitation is an important form of therapy for a patient in that situation.
Visual perception impairments are a very common part of a brain injury. Often, after other side-effects have faded, people continue to have difficulty with binocular function. The good news is that thanks to a phenomenon known as neuro-plasticity, it is possible for people with visual difficulties to recover, however it requires careful neuro-visual rehabilitation.
How Neuro-Visual Rehabilitation Works
Neuro-visual rehabilitation involves helping people to recover their visual acuity and their visual field – meaning the central and peripheral range of vision, as well as their ability to understand what is seen, process movement, and remember information that they see.
Some people struggle with depth perception, the ability to converge images from both eyes, and the ability to track an object as it moves towards them or away from them, as well as the ability to focus on objects at different distances, and the ability to scan from one part of the room to another.
Others struggle with the ability to relate sight and sound, the ability to ‘fill in the gaps’ when they see only part of a picture, and the ability to understand where one object is in relation to another.
In cases where someone has one eye significantly weaker than the other, if the retina is fine, then the difficulty could be in the brain – and the reason the weaker eye is ‘lazy’ is because of learned nonuse. The stronger eye becomes dominant in the brain, and the neural maps for using and understanding the weaker eye never grow.
Sometimes, a person becomes blind in half of their field of vision. An eye doctor may teach a patient to scan around the area where they have lost vision so that they are not at risk of falling over, or bumping into things that are within their lost field of vision. This helps them to cope with the disability, but remediation in this way is hard, and it takes a lot of patience.
Some people develop double vision, and in this case they may be encouraged to suppress the vision in one eye in order to stop the double vision, but this is only used if prisms or lenses cannot stop the double vision in general. Patching can eliminate double vision, but it can cause problems with hand-eye coordination, depth perception and even balance, because the patient becomes essentially monocular while one eye is patched.
Neuro-visual rehabilitation is a difficult task, and it requires learning new ways to use your eyesight, so that you are able to use what is left of your eyesight after brain injury in the best and most productive way possible; however, it is a lifeline for the people that it works well for, and it allows them to lead a relatively normal life and carry out normal day to day activities in spite of their difficulties and their limitations. It is a long process, but a worthwhile one.