Vision Loss After a Stroke
A stroke is a very common cause of adult disability in the US. The symptoms and damage caused by the stroke are unique to the placement of the clot. Different placements cause a lack of oxygen in different parts of the brain.
Severity and symptoms of vision loss are highly varied based on the individual and the placement of the blood clot. Changes in eyesight are more common when the stroke occurs in the right hemisphere of the brain.
Vision Changes Due to Stroke
The loss of oxygen flow to the right side can impair visual pathways resulting in many changes to your vision.
Hemianopia
Visual field loss, also known as hemianopia, is when the sufferer is unable to see to the left or right of the center of their field of vision. It can look like a black curtain hung over half of their vision in both eyes. Some cases of Hemianopia are more severe than others.
When the sufferer isn’t aware that they are experiencing a shortened field of vision it can be dangerous. Increased scanning techniques can be learned to compensate for smaller vision field. Reading becomes difficult with Hemianopia, but a typoscope (card with a cutout for the words) can be a helpful tool to make reading enjoyable again.
Diplopia
Diplopia is an eye muscle and nerve problem where the eyes move independently of each other. Diplopia or double vision can affect many everyday activities. Treatment options include prisms, therapy exercises, or occlusion.
Visual Neglect
Visual neglect is very common in right side stroke victims. Neglect is characterized by ignoring food on half of your plate, shaving half of your face, or ignoring people in half of the room. It can be problematic when the sufferer runs into objects or people on that side of their body. Treatment options are prisms or occlusion. Increased awareness strategies are sometimes effective.
Light Sensitivity
Light sensitivity can be aided by tinted glasses or sunglasses.
Dry eye
Forgetting to close eyelids completely or partial blink is a symptom that can accompany a stroke. Try artificial tears and actively full-blinking often to counteract dry eye.
Oculomotor Dysfunction
The inability for eyes to move smoothly from one object to another. Therapy is the next step for someone with “jerky eyes”, to keep eyes from becoming so fatigued and increase eye movement accuracy.
Visual balance disorders
Changed visual perception can effect body posture, training may be necessary to adjust to the new vision impairment.
There are parts of the brain that process visual information that may also be effected by the stroke. Changes in depth perception and movement may be less accurate. As with many of the side effects from a stroke, most vision problems can improve with time and treatment.
Treatments for Vision Loss After a Stroke
Glasses
Perhaps a new glasses prescription can be enough to compensate for the vision damage done by the stroke.
Prisms
Prisms are filters that change neurological pathways to affect the connections between the eye and brain. The prism will make the objects in vision appear shifted, then the observer will have to adjust their exercise to compensate for the vision shift as opposed to the actual location of the object.
The therapy is meant to increase a person’s sensitivity to Just Noticeable Differences (JND’s), with changes in size, shape, and/or orientation. Sharpening skills in picking up JND’s can improve the quality of vision and life for the stroke victim experiencing vision changes. Prisms can also be implemented in glasses to right any changes in vision.
Computer Orthoptics
There has been a development of computer therapy that has games to improve vision abilities.
Orthoptists and low-vision specialists are specialists that aid in rehabilitation for vision problems using visual training that can be supplemented with optical aids.
Improvements in vision can be seen as early as four months post stroke, but the level of improvement and impairment is very dependent on the what kind of stroke occurred.
Ask your doctor about eligibility for sight impaired or severely sight impaired, such diagnoses can help to connect with the support that may be needed.
