By Andrew Hickey on Sep 29, 2022 @ 10:25 AM
September is CVI Awareness Month, named for Cortical Visual Impairment. It is important to be aware of the symptoms, risk factors, and warning signs of this misunderstood disorder.
- Cortical Visual Impairment is a leading cause of vision loss among children
- Unlike normal vision, CVI affects the way objects can be received and recognized by the brain
- Cortical Visual Impairment commonly occurs during pregnancy
- Cortical Visual Impairment Awareness is key to intervention, as it can often go undetected
Cortical Visual Impairment, also known as Cerebral Visual Impairment or CVI, is a vision disorder that is prevalent in infants and children. CVI is not caused by an issue with the eyes. Rather it is a cognitive issue in which the brain has difficulty processing images received by the eyes. People who suffer from CVI often have no issues with their eyes, making this disorder difficult to detect with a standard eye exam.
CVI is the leading cause of vision loss among children in the United States and other developed countries. Early intervention is key to lessening symptoms and improving vision over time. Understanding the symptoms of CVI can help parents better navigate their child’s vision problems and seek the proper treatment.
Symptoms of CVI:
- Slow reactions to visual cues
- Difficulty responding to things that one sees
- Only seeing certain parts of what is happening, particularly in busy moving scenes
- Difficulty recognizing faces and objects
- Fascination with things that are moving
- Fascination with objects in a certain part of the vision like peripheral or side vision
- Trouble locating or recognizing objects in cluttered or busy spaces
- Cognitive difficulties in hand-eye coordination or reaching for objects while looking at them
- Difficulty understanding what is being looked at or seen
- Lowered sensitivity to light
Common risk factors of CVI:
- Developmental disabilities
- Cerebral palsy (a brain disorder that causes movement problems)
- Epilepsy (a brain disorder that causes seizures)
- Hearing loss
If your child is displaying any of these symptoms and/or suffers from any of the common risk factors of CVI, it is important to dive deeper into the root cause of their vision problems and consider the possibility of CVI with their primary care doctor.
Normal vision versus vision in CVI
In individuals with normal working vision, the eyes function as a camera and record a picture of an object. It travels through the optic nerves and is received and recognized by the brain. The brain then associates the images with recognized objects and works in tandem with the body’s other senses (touch, smell, hearing, taste) and sends a message to the correlating part of the body.
So, for example, if someone hands you a plate of food, your eyes capture a picture of that plate of food. Your brain then works with your sense of smell and touch to identify it as food. And then it sends a message to your hands to take and receive the plate of food.
However, in individuals with CVI, this process is interrupted. While their eyes function normally, their brains have difficulty performing their part of this normal bodily function. The brain cannot comprehend the image it is receiving due to abnormal brain function, and or damage to the optic pathways through which the visual image travels. This process interruption is what causes vision disruptions in individuals with CVI, such as blind spots or other visual abnormalities.
Who is affected by CVI?
As we have discussed, CVI is caused not by damage to the eyes or optical function, but rather by damage or issues with the brain. In most cases, this damage to the brain is caused in fetuses or infants, affecting children the most. Babies who are born prematurely are the most at risk for developing CVI, as the common causes of CVI align with common risks of premature birth. Infants who experience the following conditions are more at risk for CVI:
- Lack of oxygen or blood supply to the brain — often because of a stroke
- Hydrocephalus (when fluid builds up in the brain)
- Infections that reach the brain
- Head injury
- Certain genetic conditions
CVI is the leading cause of visual impairment in children in developed countries. It affects more than 10% of all children with developmental disabilities. By understanding who is at risk, you can help spread awareness and contribute to the improvement of CVI.
Why CVI awareness is important
September is CVI Awareness Month, and we are spreading awareness of the disorder, as CVI can be misunderstood. Many people assume that all vision problems stem from damage or issues with the eyes and/or optical function. But since Cortical Visual Impairment is a brain disorder that affects vision, it can often go undetected.
Improving symptoms of CVI is possible with the right medical care. Intervention for CVI is most effective in slowing the progression of vision problems when it is implemented early. Through targeted treatment, your child can develop new optical pathways around the damaged areas of the brain to help them better receive and process optical images.