Problems with vision make life harder for the person with the injury. Because it can take many months for the brain to recover, it may be a while before we know what, if any, problems the person will end up with.
An eye doctor will decide what, if any treatment is needed (like surgery or glasses). Sometimes the person has to learn new skills to adjust to the change in his vision. An occupational therapist can help teach these new skills Normal vision depends on the functions below working together. The brain controls all these functions. If something goes wrong at any point, vision will be affected:
- the eyes must move together and focus on something
- nerve receptors at the back of the eye (retina) must then send messages back along the optic nerve
- the occipital lobe at the back of the brain must catch or capture these messages
Some vision problems that can happen after brain injury
Blurred vision: This can be like being near-sighted. Things close up may be clear, but things that are further away tend to blur into the background.
Double vision (diplopia): This happens when the eyes don’t move exactly together, causing the person to see two of everything. This makes it hard to decide exactly where objects are.
Someone with double vision is likely to bump into furniture or drop or spill things. Sometimes an eye patch or glasses with prism lenses are prescribed.
To help someone with this problem, things such as furniture need to stay in place and not be moved without telling the person first.
Drooping eyelid (ptosis): A drooping eyelid may block vision in the affected eye. It may take awhile for vision to adjust even if the eyelid stops drooping.
It’s hard to judge distances using only one eye. The person with the brain injury may:
- feel dizzy
- not see where steps are
- not be sure about how fast things and people are moving towards him
- have trouble pouring liquids from one container to another
Hemianopia: Blindness involving one-half of the visual field in both eyes.
Vision loss: Damage to some part of the nervous system that sends messages from the eye to the brain may cause vision loss. This loss can range from some vision loss to complete vision loss. Often some part of the visual field may be missing. For example, he may not see things to his left, but be able to see things on his right.
People with some loss of their visual field may:
- suddenly notice objects that seem to appear or disappear as they can’t see that part of their environment
- bump into objects on the affected side
- not see food on the side of the plate on the affected side
- turn their head toward the unaffected side
- lose track of the last place on a page where they were reading or writing
- cut words in half when reading, which can make it hard to figure out what the word is
To help someone with visual changes
- Remind him to look around the environment, especially on the affected side.
- Mark “on” and “off” switches of items that are used often (like the TV and kitchen appliances) with bright pieces of tape so the person can tell when equipment is on or off.
- Put bright objects or favourite things on the affected side and him to turn his head until he sees the objects.
- Make the font or print size bigger.
- Draw a straight, brightly coloured line down one side of a book or notebook as a cue to show the edge of the page. Do this on the right side of the page if the right side is affected and on the left side if the left side is affected.