Down syndrome and CVI explained

Written by Hannah Mark and Rachel Bennett

Down syndrome (DS), is a genetic disorder that occurs when an individual has an extra copy of chromosome 21. Current research shows that Cortical/Cerebral Visual Impairment (CVI) is more common in neurodevelopmental conditions, including Down syndrome. In one small study, over 38% of kids with Down syndrome showed signs of CVI. Another genetic study suggested that the chromosomal abnormality in Down syndrome could contribute to the development of CVI. DS-CVI is an area of emerging research.

Signs of CVI are often missed in kids with Down syndrome, and the condition is not usually screened for during clinical visits. The challenges associated with CVI are often attributed to behavioral issues, cognitive delay, or other conditions such as autism and attention deficit disorder. Visual challenges might also be associated with other eye problems that commonly occur in Down syndrome, such as keratoconus, nystagmus, and strabismus.

Because of this diagnostic overshadowing, it is crucial to recognize CVI behaviors in Down syndrome to ensure that the individual receives the appropriate services and support to fully access their learning and their world. Because it’s brain-based, CVI has diverse manifestations, and it’s important to understand what access looks like for each person with CVI. Some with CVI use supports that allow them to use their vision without fatigue, some rely on other sensory modalities (e.g., touch, hearing, movement), and many with CVI use both their available functional visual skills and other senses.

What does CVI look like in Down syndrome?

For people with DS-CVI, and for people with CVI in general, the pattern of visual impairment will be specific to the person. Children with CVI, including those with DS-CVI, might have vision that is better sometimes and worse at other times. They might have loss of their peripheral vision, difficulty seeing where objects begin and end, and trouble recognizing what they see. Children with CVI might be more attracted to objects of specific colors and often use color-coding skills to track an unrecognizable visual world.

Being on the blindness and low vision spectrum, children with CVI often use their other senses, like touch or hearing, to navigate and support recognition. They also might only be able to focus on one sense at a time, using either their vision or their hearing, for example.

Individuals with CVI often have workarounds for everything that it might be hard to realize that they are not fully using their vision and relying on compensatory skills—like touch, hearing, memory, context, and color-coding—to engage in everyday tasks. The CVI behaviors may not become fully apparent until a child learns to read or engage in increasingly complex academic tasks. While for others, one might notice trouble going downstairs, constant tripping and falling, a head tilt, or overstimulation in busy environments.

Children with DS-CVI may exhibit many of the CVI traits and behaviors. Here are a few examples of the behaviors that families notice in their children with suspected DS-CVI:

They hold tablets or toys very close to their face or sit very close to the TV
In crowded environments, they become overwhelmed and may need to hold a parent’s hand in order to navigate.
They often sit down on the floor or flop to the ground, especially when in a crowded or noisy place
They might be easily distracted by lights and stare at them
They become distressed by motion: close their eyes when riding in the car and dislike sitting on swings
They struggle to recognize people’s faces in real life or in pictures.
They often have difficulty going up or down the stairs or walking on uneven ground.
They might clear the tops of crowded desks, or crumple up crowded worksheets.
Struggle with recognizing and learning two-dimensional images, photographs, print text, or numbers.

CVI is common, yet less than 20% of kids with CVI are diagnosed. Symptoms and traits of CVI are often misdiagnosed as another condition, and mislabeled as defiance, lack of interest, inattentiveness, or disruptive. Behavior is communication—often kids with CVI are expressing a need for access and safety in an inaccessible visual world.

DS-CVI and development

A lot of developmental milestones, like pointing, walking, or recognizing faces, depend on vision. So, because of CVI, children with DS-CVI might be delayed in reaching these milestones compared with children with DS alone.

It is very common for doctors, therapists, and families to assume that slower development in a child with DS is due to being “severely affected” by Down syndrome. By making this assumption, other causes for delay might be missed, including CVI.

It’s important to notice if a child is developing slower than their peers with DS. If they are, you should ask yourself whether this could be related to their vision and the child should be evaluated for CVI.

CVI is a lifelong condition and functional vision may improve over time due to neuroplasticity and appropriate access and supports. With early diagnosis and early intervention, we can help kids with CVI build visual skills and sensory skills that are foundational to learning.

Learning challenges in DS-CVI

Unlike kids who use their vision to watch others work and play, kids with DS-CVI may avoid looking, miss details and have trouble distinguishing faces. Therefore they have trouble learning by watching, which is called incidental learning. This can influence play skills, activities of daily living, social interactions, and concept and vocabulary development.

In a classroom, crowding, movement, and noise make it difficult for children with DS-CVI to pay attention. Because of their challenges with visual recognition, children with DS-CVI may have trouble identifying objects in pictures. They also might struggle with recognizing letters and words. This can affect their learning from books or flashcards and impact vocabulary development.

Worksheets are often difficult for children with CVI because they are visually crowded and use abstract images and line drawings. Tracing may also be difficult because of trouble with visual guidance of the hands and visual attention to following the lines. With all of these visual challenges, children with DS-CVI may become frustrated or overwhelmed in a classroom, and this can lead to behaviors like crumpling papers, getting up from the desk, putting their head down, or hiding.

Learning strategies

The DS literature discusses how many children with DS are “visual learners”—excellent observers of people and their surroundings, and typically are very good at imitation, gestures, and facial expressions. But with CVI, vision is unreliable, and kids with DS-CVI need support for their vision, adapted materials, and extra focus on learning through their other senses, including hearing and touch. Some may also learn keyboarding and braille so that they can continue to learn even with unreliable vision.

Comprehensive functional vision, CVI, and learning media assessments will collect the necessary information for the school team to decide on the most appropriate supports, services, accommodations, and program placement to ensure a student with DS-CVI has full access to the curriculum and the learning environment. Below are some examples of strategies to help a child with DS-CVI learn.

Allow for multisensory learning in all content and skill development areas, using tactile, auditory, kinesthetic, and visual sensory channels in the learning process. Many with CVI can only use one sensory channel at a time. For example, it’s difficult to look and listen simultaneously.
They may be able to attend better and focus in a quiet, calm environment.
They may benefit from hands-on learning with real objects, and using colored photographs of real objects.
Learning materials should be free of visual clutter.
They may benefit from using high-contrast backgrounds to help them distinguish shapes and letters while reading.
They might also do better with screen-based learning. The computer screen helps reduce visual clutter and background noise, provides backlighting to support visual attention, and allows the child to focus on one thing at a time.
Kids with DS-CVI may learn better when key concepts are repeated and when they can take frequent breaks.

Resources and next steps

If a child has Down syndrome and seems to struggle with their vision, they should be assessed for CVI to make sure they can learn and grow in a way that works for them. Diagnosis for CVI is based on a combination of a clinical vision exam done by an ophthalmologist, neuro-ophthalmologist, optometrist, or a medical low-vision specialist in combination with a review of medical and educational history.

The functional vision clinical assessment may include a questionnaire of behaviors, as well as numerous evaluations in a clinic examining visual behavior. If the functional vision exam shows deficits not explained by the ophthalmologic exam of the eye, the ophthalmologist will diagnose CVI. Sometimes, a functional vision evaluation by a Teacher of the Visually Impaired (TVI) can help provide information need to support a diagnosis.

Learn more about how CVI is diagnosed and educational assessments for students with CVI.
Dive into our in-depth CVI behaviors resource. Find short videos, clear explanations for each, questions for observation, example accommodations, and current research.

Down syndrome resources

Genetic study about DS CVI: Bosch, D. G., Boonstra, F. N., Reijnders, M. R., Pfundt, R., Cremers, F. P., & de Vries, B. B. (2014). Chromosomal aberrations in cerebral visual impairment. Eur J Paediatr Neurol, 18(6), 677-684. https://doi.org/10.1016/j.ejpn.2014.05.002
Study about CVI more common in DS: Wilton, G. J., Woodhouse, R., Vinuela-Navarro, V., England, R., & Woodhouse, J. M. (2021). Behavioural Features of Cerebral Visual Impairment Are Common in Children With Down Syndrome. Frontiers in human neuroscience, 15, 673342. https://doi.org/10.3389/fnhum.2021.673342
National Down Syndrome Congress
National Down Syndrome Society

Research shows that CVI may be common in Down Syndrome (DS). Learn about what CVI looks in DS, learning challenges, and examples of supports and strategies.

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