Cortical visual impairment (CVI)

How does this happen?

Seeing is a two-stage process. The eye captures an image and sends it along the visual pathways to the back of the brain. The brain then interprets it: separating an object from its background, recognizing a face, judging distance, and deciding what matters.

CVI is a failure of the second stage. The camera works; the processing does not. ¹

The visual pathways run through parts of the brain that are especially vulnerable around birth. They pass close to the ventricles, which is why periventricular leukomalacia in babies born early so often affects vision. They end at the back of the brain, in the occipital lobes, which are characteristically injured by prolonged low blood sugar. And they are affected by widespread injury after severe hypoxic-ischemic encephalopathy. ²

That is why CVI is common after birth injury and why it is so frequently missed. Everyone is watching the arms and legs.

What causes it?

Two different questions get mixed together here. The first is what leads to this injury in the body. The second is whether anyone could have prevented it. They are not the same question, and the answer to the first does not settle the second.

Happens even with perfect care

• periventricular leukomalacia and white matter injury after preterm birth. ²
• hypoxic-ischemic encephalopathy, particularly where injury is widespread. ⁴
• Perinatal stroke. ⁵
• Bleeding in the brain. ⁶
• meningitis and other brain infections.
• Brain malformations and genetic conditions.
• Seizures and epilepsy, which can affect visual processing. ⁷

Associated with gaps in care

These are situations where published standards say what the care team should watch for and do. A gap here does not prove anyone caused your child's injury. It points to where the medical records will have an answer.

CVI is more often a consequence of an injury than something caused by a specific gap. The gaps that matter here are about detection.

• A child at known risk never assessed for CVI. Children with brain injury are a group in whom vision should be actively assessed rather than assumed. ¹
• A normal eye exam treated as ruling out a vision problem. An eye exam does not test visual processing. ¹
• Low blood sugar not screened for or not treated, which is a direct cause of occipital injury. ⁸
• A loss of oxygen during labor not acted on. ⁹
• No functional vision assessment before school, so a child was taught as though they could see typically.

Whether any of this changed the outcome in a particular case takes a physician expert reading the whole record.

What are the signs, by age?

Signs change as a child grows. A newborn cannot show you a walking problem. Some children look fine at first and show differences months later.

At birth and the first hours

Nothing measurable. Newborn vision is limited in all babies, so CVI cannot be identified at this stage.

The first week

Nothing specific.

Around 3 months

• Not fixing on a face, or not following an object across the midline.
• Looking past or beside an object rather than at it.
• Strong preference for looking at lights, ceiling fans or windows.
• No visual response in a baby who otherwise seems alert.

Around 6 months

• Reaching for an object without looking at it, or looking then looking away before reaching.
• Finding a toy on a plain surface but not in a busy one.
• Preference for a single strongly colored object, often red or yellow.
• Better response to moving objects than to still ones.

Around 12 months

• Difficulty in new environments while managing familiar ones well.
• Bumping into things on one side, which can indicate a visual field loss.
• Looking down at the floor while walking.
• Vision that seems worse when the child is tired.

Toddler years

• Difficulty finding a person in a group, or a shoe in a pile.
• Difficulty on stairs, curbs and changes in floor surface.
• Distress in busy, visually noisy places.
• Difficulty recognizing faces, sometimes including familiar ones.

School age

• Difficulty reading a crowded worksheet while managing a plain one.
• Losing place on the page.
• Fatigue after visual tasks.
• Being described as inattentive or careless when the real problem is visual.

How is it diagnosed?

CVI is diagnosed by putting three things together: an eye examination that does not explain the vision, a history of brain injury or risk, and a pattern of visual behavior that fits. ¹

An ophthalmologist checks eye health, refraction and eye movements. This step is essential and it is not sufficient. Children can have both an eye problem and CVI. ¹

A functional vision assessment is the one that answers the question. It is usually done by a teacher of the visually impaired, an orientation and mobility specialist, or a vision team, and it looks at how a child uses vision in real settings: with clutter and without, near and far, tired and rested, with movement and without.

MRI shows the underlying injury, particularly in the occipital lobes and the visual pathways. ²

The single most useful thing you can bring

Video and notes from home. Film your child finding a toy on a plain blanket and then in a toy box. Note the time of day, whether they were tired, and how noisy the room was. That evidence is often more informative than a clinic test, because CVI varies and a clinic visit is one sample.

What to insist on

If your child has a brain injury and you are told their vision is fine because the eye exam was normal, ask specifically: "Has anyone assessed for cortical visual impairment?" Use those words. ¹

What is the treatment?

There is no medicine and no surgery for CVI. What works is changing what the child is asked to look at, and how.

Reduce clutter. A single object on a plain background instead of a crowded tray. This is the highest-value change and it costs nothing.

Increase contrast. A yellow cup on a black placemat. A dark plate for light food.

One thing at a time. Present, then wait. Many children with CVI need several seconds of looking time before they respond, and a second object arriving in that gap resets the process.

Reduce competing input. Turn off background noise while a child is looking. Looking and listening compete for the same processing capacity in CVI.

Use movement and light to draw attention initially, then fade them.

Allow looking and reaching to be separate. Many children look, look away, then reach. That is efficient for them, not a mistake.

Watch for fatigue. Vision is usually worse when the child is tired, unwell or overwhelmed. Schedule visual work accordingly.

Get the school plan right. Federal rules require the written plan to describe how the disability affects participation and to set out services and accommodations. ³ A teacher of the visually impaired should be involved. Plain worksheets, uncluttered displays, extra looking time, and preferential seating all belong there.

Early intervention services include vision support for children under 3. ¹⁰

What is the long-term outlook?

Vision in CVI often improves over time, particularly with the right environment and teaching. This is one of the more encouraging facts in this whole library, and families are often not told it. ¹

What usually improves: the ability to handle more complexity, to look and reach at the same time, and to function in less-controlled environments.

What often persists: difficulty in visually noisy settings, difficulty recognizing faces, and vision that fluctuates with fatigue.

Outcome is also shaped by the underlying brain injury and by whether the child gets a proper functional assessment and appropriate teaching. A child taught as though they see typically will struggle for reasons nobody is naming.

What does daily life look like?

Homes change. Plain backgrounds, less on the walls, one toy out at a time, high contrast at mealtimes.

The most common family experience is realizing that behavior they read as inattention or stubbornness was a vision problem all along. That reframe changes daily life more than any equipment.

At school, the child needs an uncluttered visual environment and time. Both are easy to provide and both need to be written down, because they will otherwise disappear when a new teacher arrives.

What does care cost over a lifetime?

CDC estimated the lifetime cost associated with vision impairment at about $566,000 per person in 2003 dollars for those born in 2000. ¹¹ That estimate is for vision impairment generally, not for CVI specifically, and no agency publishes a CVI-specific figure.

Where CVI accompanies cerebral palsy, the estimates overlap and cannot be added together for one child. ¹¹

See the cost of care estimator.

What can you do this week?

1. Ask directly: "Has my child been assessed for cortical visual impairment?" Use those words.
2. Ask for a functional vision assessment, not just an eye exam.
3. Try one change today: put a single toy on a plain blanket and watch what happens.
4. Film your child looking, in a plain setting and a busy one, and bring the videos.
5. Ask for a teacher of the visually impaired through early intervention or the school.
6. Ask what the MRI showed in the occipital lobes and visual pathways.

What should you ask each specialist?

Take these with you. Write the answers down in the moment, because you will not remember them later.

For the ophthalmologist

• Is there anything wrong with the eye itself?
• Does the eye exam explain what we are seeing at home?
• Could this be cortical visual impairment?
• Who does functional vision assessments here?

For the vision teacher or CVI specialist

• What specifically helps my child see better?
• How much looking time does my child need?
• What should the classroom look like?
• How will we measure whether vision is improving?

For the neurologist

• What did the MRI show in the visual pathways and occipital lobes?
• Could seizures be affecting vision?
• Is there a visual field loss?

You can also build a printable list with the question generator.