Cortical Visual Impairment (CVI): Symptoms, Causes, Support

Cortical visual impairment (CVI), also called cerebral visual impairment, is vision loss caused by the brain rather than the eyes: the parts of the brain that process vision are damaged or don't work as they should, so a child can see poorly even when an eye problem doesn't explain it. The National Eye Institute (NEI) calls it a leading cause of vision loss among children in the United States. Most children with CVI aren't totally blind, and many see better as they grow, though the sources disagree on how much.

Below: what CVI is and why it has two names, its causes and signs, including Christine Roman-Lantzy's 10 characteristics, how it's diagnosed and by whom, the CVI Range and its phases, whether it gets better, what helps, what happens at school, braille or print, and vision loss from the brain in adults. Sources were checked on October 30, 2026. This article explains what those sources say; it isn't medical advice. If you're worried about a child's vision, talk to their pediatrician or an eye doctor.

In the UK, "CVI" also stands for the Certificate of Vision Impairment, the form used to certify someone as sight impaired. That's a different thing, explained in registered blind in the UK.

Key points

• The brain, not the eyes. The eyes may be healthy, or have problems that don't explain how poorly the child sees. A normal eye exam doesn't rule CVI out.
• Two names, one condition. Cortical and cerebral visual impairment are used for the same thing; the NIH working group says "cerebral" has become more widespread.
• Common in children. Every source we read ranks it among the main causes of vision loss in children.
• Causes are injuries or abnormalities in the developing brain, most often before, during or shortly after birth: lack of oxygen or blood flow, prematurity, infections, head injury, hydrocephalus, seizures, genetic and metabolic conditions.
• Doctors diagnose it, teachers assess it. There's no single test. An eye doctor makes the diagnosis, sometimes with a neurologist; a teacher of the visually impaired (TVI) then assesses how the child uses vision.
• No cure, but vision often improves. How much varies, and sources differ. Support means adapting the child's surroundings, materials and teaching.
• At school, the IEP team uses the TVI's assessments to choose print, braille, audio or, most often, a mix.

CVI and related terms at a glance

What is cortical visual impairment?

CVI happens when the eyes can send signals but the brain has trouble turning them into what we see. NEI describes it as "a disorder caused by damage to the parts of the brain that process vision" that is most common in babies and young children but can continue into adulthood (NEI). The American Association for Pediatric Ophthalmology and Strabismus (AAPOS) puts it simply, for children: the eyes work fine and take pictures, "but the brain can't understand the pictures" (AAPOS).

In 2024, a working group from a National Institutes of Health (NIH) workshop published a working definition with five parts (Chang and Merabet, Ophthalmology, 2024). In plain words:

1. CVI is a spectrum of visual impairments caused by an abnormality in the brain that affects how visual processing develops.
2. The vision problems are greater than any eye condition the child also has would explain on its own.
3. It can affect basic vision, such as sharpness and the visual field, and also higher-level processing, such as recognizing faces and objects or finding something in a busy scene.
4. It can come with other conditions, but it isn't mainly a disorder of language, learning or social communication.
5. The brain injury behind it may go unnoticed or undiagnosed until later in life.

The same paper says children with CVI are "usually not completely blind": they have some vision, which may improve over time. For where US law draws the line for blindness, see what is legally blind.

How common is CVI?

All the sources agree it's common in children, but they word it differently:

• NEI: "a leading cause of vision loss among kids in the United States."
• American Academy of Pediatrics (AAP): "one of the most common causes of vision loss in children in the United States" (HealthyChildren.org).
• Cleveland Clinic: "the leading cause of vision loss in children" (Cleveland Clinic).
• Boston Children's Hospital: "the most common cause of permanent visual impairment in children" (Boston Children's).
• APH CVI Advisory Group (2010): about 30% to 40% of children with visual impairments have CVI (statement on AFB).

Perkins School for the Blind estimates, from health insurance data analyzed with McKinsey, at least 180,449 patients with diagnosed or likely CVI in the US, and a diagnosis rate under 20% (Perkins). That's an estimate by one organization, not an official count.

Cortical or cerebral visual impairment?

Both names refer to the same condition, and you'll find both on reputable sites. NEI, AAPOS and the NIH working group lead with "cerebral"; Cleveland Clinic and the Pediatric Cortical Visual Impairment Society (PCVIS) lead with "cortical."

The reason for the shift: the cortex is the brain's outer layer, but CVI can also involve the white matter underneath and other visual areas. The NIH paper says "cortical visual impairment" was the term in the original report, and "cerebral visual impairment" has since become more widespread because those deeper structures may be involved. Boston Children's calls "cortical" misleading for the same reason. A 2010 statement by an advisory group of the American Printing House for the Blind (APH) treats cortical visual impairment as a subset of cerebral visual impairment. The NIH group lists standard naming as work still to be done.

"Cortical blindness" is a different story. AAPOS calls it an old name for CVI in children that it no longer uses, "because most kids with CVI can see some things." In adults, the term is still used for a specific kind of vision loss, covered at the end.

What causes CVI?

CVI is caused by an injury to the brain or by a condition that affects it, most of the time before, during or shortly after birth. NEI lists these common causes in babies and young children:

• 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

NEI adds that babies born prematurely are more likely to have CVI. Cleveland Clinic says a lack of oxygen to the brain at birth, called hypoxic-ischemic encephalopathy, is the most common cause. The NIH paper also names prematurity with periventricular leukomalacia (damage to white matter near the brain's ventricles), seizures and metabolic conditions.

Children with CVI often have other conditions too. NEI names developmental disabilities, cerebral palsy, epilepsy and hearing loss; Cleveland Clinic adds autism, learning disabilities and sleep disorders.

Signs of CVI

NEI says kids with CVI may have trouble responding to what they see, seeing busy moving scenes, recognizing faces and objects, finding things in cluttered spaces, reaching for something while looking at it, and understanding what they're looking at. Parents may notice that a child reacts slowly to what they see, prefers things that move, or prefers to look with one part of their vision, such as the side. Some kids stare at lights; others are sensitive to light.

Roman-Lantzy's 10 characteristics of CVI

Christine Roman-Lantzy, PhD, describes 10 characteristics of visual behavior in her textbook Cortical Visual Impairment: An Approach to Assessment and Intervention, measured with her assessment, the CVI Range. PCVIS publishes them with her permission (PCVIS). Summarized:

1. Color preference: a strong attraction to a particular color, or to bright, saturated color.
2. Visual latency: slow or delayed looking; given enough time, the child may turn toward the object.
3. Need for movement: attraction to moving objects, or shiny ones that seem to move.
4. Visual field preferences: ignoring some areas of the visual field, or turning the head to look from one part of it.
5. Difficulties with visual complexity: busy patterns on objects, competing sounds and other senses, crowded scenes, and faces.
6. Need for light: an unusual attraction to light, sometimes gazing at lights for a long time.
7. Atypical visual reflexes: unusual blink and threat responses, the reflexes that protect the eyes.
8. Absence of visually guided reach: trouble looking and reaching at the same time; some children look, look away, then reach.
9. Difficulty with distance viewing: behaving as if very nearsighted, even with large or familiar objects farther away.
10. Difficulty with visual novelty: preferring familiar things and ignoring new ones.

A single sign doesn't mean CVI. Boston Children's says "a child showing only one or two of the behaviors above does not indicate CVI," and the APH group says a combination of these features is needed to confirm a diagnosis. The NIH paper adds that conditions that often come with CVI, such as autism, can look similar and make the diagnosis harder. That's why the next step is an exam, not a checklist.

How CVI is diagnosed, and who does it

"There's no single test to check for CVI," says NEI. The usual path, from NEI and the AAP:

1. A complete eye exam to see whether a problem in the eyes explains the child's vision. The AAP suggests asking the pediatrician for a referral to a pediatric ophthalmologist, who also goes over the child's history and the behaviors parents have noticed.
2. If the eyes don't explain it, an eye doctor familiar with CVI. NEI says the child may also need a pediatric neurologist or a neuro-ophthalmologist, and doctors may order brain scans.

PCVIS says the diagnosis is usually made by an ophthalmologist, neuro-ophthalmologist or neurologist, and that in some states an optometrist may diagnose CVI. Two points from the NIH paper: a normal result on the standard eye exam "does not exclude the presence of CVI," and brain imaging and genetic tests may help, but abnormal results aren't required for the diagnosis. PCVIS adds that brain scans "may or may not" show the cause. The NIH group also proposed the term "CVI suspect" for children with a strong suspicion who still need more testing.

The diagnosis is only the start. After it, the AAP says the child is referred for a vision services evaluation, through early intervention (birth to 3) or the school, and a teacher of the visually impaired does several evaluations: how the child uses vision, how they use other senses, and what technology helps. That's the functional vision assessment. The APH group says the TVI should lead it, and warns that traditional functional vision assessment tools don't adequately assess the visual behaviors typical of CVI, so they should be assessed directly. Our guide to the teacher of the visually impaired explains what a TVI does.

The CVI Range and the three phases

The CVI Range is Roman-Lantzy's assessment of how a child with CVI uses vision. It combines a caregiver interview, observation and direct assessment of the 10 characteristics, and gives a score from 0 to 10, where higher means more typical functional vision. That description comes from a 2022 study protocol, by Melinda Chang, Roman-Lantzy and colleagues, that adapts it for clinical research (PCVIS summary of Chang et al., BMJ Open Ophthalmology, 2022); the same page says the CVI Range is widely used in education. It describes functional vision; the diagnosis itself comes from a doctor.

Scores are grouped into three phases, each with its own goal, as PCVIS describes them:

• Phase I: "building consistent visual behavior." PCVIS says this can happen only when the environment and materials are highly controlled. A 2020 handout from Dr. Roman says a child in Phase I notices objects only up close, within 12 to 18 inches (TSBVI).
• Phase II: "integrating vision with function." The child now looks consistently and starts to look directly at objects and act on them. PCVIS warns: "Do not confuse looking with interpreting" (Phase II).
• Phase III: "refine the CVI characteristics." Vision is greatly improved, but PCVIS says the student "remains visually impaired" and that "It is not typical for a student to score above a 9 on the CVI Range" (Phase III).

The boundaries are written two ways. The 2022 protocol groups scores as Phase I from 0 to 3, Phase II from 3 to 7 and Phase III from 7 to 10. Dr. Roman's 2020 handout puts Phase II at "above 3 to 7" and Phase III at "above 7."

Does CVI get better?

Often, yes, but nobody can promise how much, and the sources describe it differently:

• APH CVI Advisory Group (2010): "nearly all children with CVI will demonstrate improved vision," and many characteristics resolve, but most children still meet the definition of CVI.
• Cleveland Clinic: most children see some improvement as they grow, but for some, "vision challenges stay the same or get worse."
• NEI: for some people, vision problems get better over time on their own, and "Experts aren't sure why this happens."
• AAPOS: sight might get better as the brain grows, but "it's hard to know how much better."
• Boston Children's: "In many cases, partial recovery of vision is possible."
• PCVIS (Roman-Lantzy): with early, appropriate intervention the characteristics improve but "will never fully resolve"; CVI is "a lifelong condition."

Only the child's own doctors and TVI can speak to a specific child.

Is there a treatment for CVI?

There's no cure. NEI, the AAP and Cleveland Clinic all say so. The NIH paper says care today focuses on "environmental adaptations, accommodations, and habilitation," plus treating any eye conditions, and that research is still needed to find evidence-based medical treatments specific to CVI.

What the sources describe instead:

• Treating what can be treated. The AAP says the eye doctor treats any eye problems, and the pediatrician and a pediatric neurologist work on underlying brain problems.
• Vision rehabilitation and low vision services, to make the most of the vision a child has (NEI, AAP).
• Early intervention, therapy and educational support (NEI), with diagnosis and vision services as early as possible (AAP).
• Changes at home and school. Cleveland Clinic's examples: less visual clutter, such as patterned rugs or dishes; no vision tasks when the child is hungry, tired or upset; family or teachers wearing the same bright item each time; lower room lights and backlit screens; big, colorful, high-contrast or moving objects; more space between lines of text, with extra text blocked out; and touch or sound to get the child's attention. AAPOS suggests big, bright, moving toys.

These are general examples. Which ones fit a child is for the child's team to decide.

CVI at school: IEP, TVI, FVA and LMA

In the US, the Individuals with Disabilities Education Act (IDEA) covers two plans: the Individualized Family Service Plan (IFSP) for early intervention from birth to 3, and the Individualized Education Program (IEP) at school (PCVIS).

What the sources say should happen for a child with CVI:

• The TVI leads the functional vision assessment (FVA) and shares it with the team, according to the APH group; its findings feed the learning media assessment (LMA), the expanded core curriculum and the IFSP or IEP. Orientation and mobility is planned with a certified specialist.
• A "CVI-rich IEP": PCVIS says services and accommodations should be based on the child's CVI Range score and the 10 characteristics, with vision breaks during the day.
• The LMA decides the reading media. Perkins says that if a student is blind or has low vision, including CVI, the school must do an LMA to decide whether braille, print, auditory tools or a combination work best (Perkins).

What each assessment covers, who does it and what the law says are in our guide to the functional vision assessment and learning media assessment.

Braille or print for a child with CVI?

There's no single answer, and the sources don't give a rule. Perkins says the LMA may point to adapted print and visuals, braille, tactile, digital or audio formats, "or, most often, a combination." It adds that even when a student with CVI can read print with adaptations, print "may not be the most efficient, reliable, and comfortable way to access literacy"; for some, it becomes uncomfortable and tiring at points in the school day.

In a Perkins interview on dual media, TVI Tammy Reisman says: "Some kids might be learning print, but they might need braille." She describes a student who started with tactile symbols and now reads print: after 10 minutes her eyes get tired, and she goes back to braille or tactile symbols (Perkins).

For children working toward print, PCVIS describes Roman-Lantzy's visual literacy approach: real objects first, then other versions of the same object, then the object paired with its photo, then its key visual features, before symbols and words (PCVIS).

If braille is part of the plan for a young child, our guide to pre-braille skills covers the touch and hand skills that come before it.

CVI in adults: cortical blindness and vision loss after a stroke

Vision loss from the brain can also start in adulthood, but it isn't the same as childhood CVI. The NIH paper describes cortical blindness in adults as complete or near-complete vision loss caused by damage to both sides of the occipital cortex, the brain's main visual area, most often after a stroke affecting the back of the brain. Children with CVI, by contrast, usually have some vision.

NEI says vision problems after a brain injury or stroke are sometimes called acquired CVI, "but it isn't the same as CVI," and usually have different symptoms. Cleveland Clinic says the same and advises seeing a provider right away about vision changes, especially after a head injury. NEI suggests asking the doctor about vision rehabilitation.

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Frequently asked questions

What is cortical visual impairment?

Vision loss caused by the brain rather than the eyes. The parts of the brain that process vision are damaged or don't work as they should, so a child sees less than any eye problem would explain. NEI calls it a leading cause of vision loss among children in the US.

Is cortical visual impairment the same as cerebral visual impairment?

Yes, both names are used for the same condition. "Cerebral" is now more common in medical writing, because the damage can go beyond the cortex; NEI, AAPOS and the NIH working group use it. Cleveland Clinic and PCVIS still use "cortical."

What are the symptoms of CVI?

NEI lists trouble responding to what the child sees, recognizing faces and objects, seeing in cluttered or busy scenes, and reaching while looking, along with slow reactions, a preference for moving things and staring at lights. Roman-Lantzy describes 10 characteristics. One or two of these alone don't mean CVI; only a doctor can diagnose it.

How is CVI diagnosed?

There's no single test. A complete eye exam comes first; if the eyes don't explain the child's vision, an eye doctor familiar with CVI, sometimes with a neurologist or neuro-ophthalmologist, makes the diagnosis. A normal eye exam doesn't rule CVI out, and brain scans may or may not show the cause.

Is there a cure for cortical visual impairment?

No. NEI, the AAP and Cleveland Clinic all say there's no cure. Support focuses on treating any eye problems, vision rehabilitation, early intervention and changes to the child's surroundings, materials and teaching.

Can a child with CVI improve?

Vision often improves, but the sources differ on how much. The APH group says nearly all children improve yet most still meet the definition; Cleveland Clinic says some stay the same or get worse; PCVIS calls CVI lifelong.

Is a child with CVI blind?

Usually not totally. The NIH paper says children with CVI are usually not completely blind, and AAPOS dropped the name "cortical blindness" because most kids with CVI can see some things. How much a child sees varies widely.

What does CVI mean in the UK?

In the UK, CVI also stands for the Certificate of Vision Impairment, the form used to certify someone as sight impaired or severely sight impaired. It's unrelated to cortical visual impairment; see registered blind in the UK.