Eye movement problems, visual processing challenges, central vision loss and visual field loss are common stroke-led vision disturbances. About two-thirds of stroke survivors suffer from vision impairment. How an individual is affected depends on exactly where the stroke occurred in the brain. Post-stroke vision problems can fall into two categories – vision loss (or vision field loss) and vision perception problems.
An individual’s vision depends on eyes to receive information and the brain to process that information. The nerves from each eye are connected to the occipital cortex at the back of the brain, allowing an individual to see. Since most strokes affect one side of the brain, the left side vision in each eye may be affected if the right side of your brain is damaged. Visual field loss after stroke may include Homonymous Hemianopia (visual field loss on the left or right side of the vertical midline) and Quadrantanopia (blindness in a quarter of the visual field).
Stroke-led damage to brainstem makes it difficult to process what the eye sees, also known as vision perception problems. One may find it difficult to coordinate movement and focus eyes resulting in double vision. It may affect the stroke survivor’s ability to blink, resulting in dry eyes. Common perception problems such as Visual neglect (also called inattention) and Agnosia (inability to interpret sensations and hence to recognize things as a result of brain damage after stroke) can often be complemented with double vision.
People who experience vision loss following a stroke do not fully recover their vision. Some recovery, in the first few months after a stroke, is possible. Certain equipment, home modifications and compensation techniques can help an individual with vision loss live independently and safely.
If your brain is correctly processing visual input but still suffers from stroke-led poor vision, then the muscles that control eyes could be the reason behind the vision loss. In such scenario, neuromuscular treatment (eye exercises) can help. Eye exercises workout the 6 muscles that control the eye and make them stronger.
Because many perception problems are caused by the lack of muscle control, various exercises focused on building up muscle control can be effective. Also, treatment by Prisms lenses can also be helpful in correcting many perception issues such as double vision, depth perception, visual neglect and visual midline shift. In some cases, eye muscle surgery can be used to correct double vision.
Visual Restoration Therapy could be used to stimulate Neuroplasticity and encourages the brain to rewire itself. By stimulating the border between “good” and “blind” spots in your field of vision, eyes may regain their ability to interpret what they see.