Vision problems and symptoms are among the most common difficulties associated with acquired brain injuries. The nerve systems that control the way the eyes work and focus together, and transmit the visual information to the back of the brain for understanding of our visual world, are the most complex systems of the brain. Vision enables us to be aware of our surroundings and to know where we are in our world, to steer our walking through our environment, to direct hand and other actions to write and hold things, and to help us stay balanced.
Since vision systems are in many parts of the brain, it is possible for any insult to the brain to lead to significant effects on a person's ability to read, drive, walk and work. A vision problem can also restrict a person's ability to benefit as much as possible from rehabilitation services.
Brain injuries which may cause visual problems can result from:
- Cerebrovascular accident (stroke)
- Motor vehicle accident / motor bike accident
- Bicycle accident
- Skateboard accident
- Whiplash
- Falls
- Assault
- Gunshot wounds
- Sporting head injuries and concussion
- Domestic violence, including child abuse
- Drowning / electrical shock / poisoning
Injury to the eye or to the brain areas associated with the visual system can result in development of the following:
- Strabismus (turned eye)
- Reduced visual acuity (sharpness of sight)
- Visual field loss (loss of vision to one side or in one area)
- Eye movement disorders
- Binocular vision dysfunctions
- Accommodation (focus) disorders
- Difficulties in visual perception
- Problems in visual motor integration (eye-hand, balance)
The symptoms of eye and vision problems associated with acquired brain injury include, but are not limited to, the following:
- Double vision
- Blurred vision
- Reduced ability to concentrate on sustained visual tasks such as reading
- Poor reading comprehension
- Headaches
- Dizziness
- Eye strain
- Difficulty reading
- Sore eyes
- ensitivity to light
The signs of such eye problems can include:
- Eye turn
- Closing or covering one eye
- Eyelid drooping
- Turning or tilting head
- Difficulty walking straight
- Bumping into objects
- Balance and coordination problems
- Poor depth judgement
- Poor eye hand coordination
- Poor awareness of surroundings
- Difficulty driving
- Sensitivity to light
- Eyes flickering quickly
Optometric Assessment and Management
The person with vision problems following brain injury should be examined by an optometrist who has special training and experience in care of eye and vision problems related to brain injury. Frequently the optometrist will work together with the occupational therapist, neurologist, general medical practitioner, and other rehabilitative specialists to relate specific visual problems to the effects on the person's ability to function in activities of daily living, as well as the ability to benefit fully from other rehabilitative services.
The optometric evaluation of a person with acquired brain injury may include:
- Comprehensive eye health assessment.
- Refraction to measure eye power.
- Assessment of focussing ability.
- Assessment of binocular vision function, to ensure single vision and depth perception.
- Low vision assessment to maximise poor vision.
- Visual field assessment to detect loss of vision at the side or elsewhere.
- Assessment of effects of vision on balance, posture and movement.
- Eye-hand coordination.
- Visual information processing.
Optometric management may include:
- Management of ocular disease either directly or by co-management with doctors.
- Spectacles for general seeing to provide clear and stable vision.
- Spectacles for near tasks such as reading and computers.
- Prisms to treat double vision, or provide more stable balance and movement.
- Total or partial patching to provide better function and comfort.
- Low vision care to maximise poor vision.
- Tints to reduce light sensitivity.
- Vision therapy to improve focusing, eye movements, eye coordination, and hand-eye coordination.
- Counselling and education of patient, family, and caregivers about the patient's visual problems, functional implications, goals, prognosis and management options.
- Consultation with other professionals involved in the rehabilitation and health care of the patient.
Absence of evidence is not evidence of absence. Frequently, acquired brain injuries can cause significant difficulties for people in using vision to walk, work and read, and yet there may not be any medical evidence (such as X-rays, MRI etc) which shows damage to the vision areas of the brain. However, the effects of brain injury on vision can significantly interfere with a person's quality of life, and ability to get better as quickly as possible. The optometrist's role is to provide essential vision services in diagnosing and treating eye and vision problems to maximise the patient's visual function and comfort, and subsequent quality of life.
