Welcome to the About CVI learning guide! These are curated resources from our larger pool of CVI content to get you started in your learning journey. Scroll through this guide to learn about CVI on a fundamental level, including causes, the impact of CVI, what you might see if you have CVI, and where the field is going.
Cerebral/Cortical Visual Impairment (CVI) is the leading cause of childhood blindness and low vision, yet it is alarmingly misunderstood and undiagnosed. CVI is a lifelong brain-based visual impairment, caused by damage to the brain’s visual pathways or visual processing areas. It’s usually diagnosed when abnormal visual responses can’t be attributed to eye problems alone.
People with CVI struggle with visual attention and visual recognition, resulting in a lack of access to the world around them. Some people see the world as distorted and unrecognizable. Others can focus but might struggle to understand what they see. A crowded setting, a hot day, or fatigue has the potential to make vision use nearly impossible.
With CVI, the brain has difficulty converting the raw data from the eye into a reliable, meaningful image of the world that can be interpreted and acted upon.
Matt Tietjen, CTVI and leader in the field
Some people have trouble with facial recognition, hand- and foot-eye coordination, or integrating vision with other senses. These behaviors may change and improve over time, but they never disappear. As such, people with CVI often develop unique compensatory skills to manage their confusing visual world.
The CVI visual behaviors are an ongoing need, they can change and improve for some, but the need never goes away. Support for CVI needs to be sustained and lifelong.
Below is a list of visual behaviors of CVI that are commonly evaluated and recognized by major theorists. No area is separated from the other—the CVI visual behaviors are highly connected—and all can impact the individual with CVI at any time. At Perkins, we also evaluate how individuals use their compensatory skills within each visual behavior.
Bella works hard to use her vision to focus on school activities, such as flower vase decorating. With CVI, creating opportunities for children to focus is crucial to helping them see more. So, teachers at Perkins School for the Blind use visual and sensory supports like lights, colors, objects, and clutter-free environments to help make focusing and looking at beautiful art projects possible.
Logan has a meaningful connection with the word “Mom,” which helps him recognize it when he sees it. For many with CVI, building a “visual library” in the brain is difficult, so recognizing items and the world can be tenuous or limited. But, with help from a simple, clean background, a backlit eye-level screen, and bold, bright color, Logan can begin to look at and understand what is in front of him.
Josian finds it much easier to reach for learning aids in a clutter-free environment. When too many items are in a room or on a table, it’s hard for many with CVI to see and recognize everything. For Josian, this simple space and background makes sure he can focus on his school tasks.
Krish uses his white cane to safely navigate all types of environments since he can’t see anything below eye level. Like Krish, some with CVI can experience lower visual field loss. But, others may experience loss in the right, left, or upper fields. For some, visual fatigue, clutter, noise, and stress can drastically reduce the field of view.
Grace is studying for the Geography Bee and relies on color to find and recognize countries on the world map. Bright, bold colors, and high contrast help many with CVI track an otherwise unrecognizable visual world.
Cyrus has a favorite water bottle, and he has worked hard to recognize it in the form of a photo. It is difficult for many with CVI to connect a 2D photograph, a black and white drawing, or an abstract symbol with the 3D object it represents. But now that Cyrus can show his speech therapist his drink selection, it’s officially snack time!
Logan challenges his visual motor skills at lunchtime, especially when spearing a carrot. Mealtime can be hard for many with CVI because it requires so many visual motor skills to work together. But, a quiet, simple space with intentional use of color and familiar items helps Logan to have an enjoyable meal!
Instead of walking from the mulch to the grass, Henry stops, sits, and feels around before scooching over to the lawn. Changes in surface and depth, and visual field loss, can make it hard to visually guide feet and legs.
Omer cannot see faces, even his twin brother’s, so he relies on voices, hairstyles, and clothing to recognize family, friends, and others. This is also true for many with CVI who may have difficulty understanding facial expressions, body language, and gestures.
Amir enjoys his story box during reading time, and a string of lights helps to support his vision. For Amir and many with CVI, light helps reinforce focus, but for others, it can be distracting and distorting. Overhead lights, light from a window, or even a sunny day can significantly impact people with CVI.
Bella takes some time to use her vision during math activities. She relies on her tactile skills to support her understanding and will use her vision if and when she is ready. For many with CVI, increased clutter, fatigue, and sensory inputs can all impact the amount of time it takes for a person to look at and/or process an item.
Grace loves dancing with her friends, but their fast motions can make it difficult for her to see them. In a constantly moving world, visually registering a fast car, a ball in mid-toss, or even a friend’s ballerina twirl, can be difficult for people with CVI.
For Madison, going to the store is just overwhelming. This loud, busy, and overstimulating environment means too much sensory competition, which makes using vision extremely difficult. So, Madison covers her eyes with a mask to give her brain and body a much needed break.
When Omer visits big, open spaces like the field at Gillette Stadium, he has a hard time seeing anything at a distance. Recognizing people or objects far away can be challenging for people with CVI. On the New England Patriots’ home turf, Omer would rather focus on his mom beside him.
Henry’s brain and body are tired, so he cannot use his vision at all. It’s time to rely on his blindness skills! Visual fatigue is a shared experience for many with CVI. It can happen after engaging in a challenging visual task for a few minutes, being in a busy environment, or feeling sick, overheated, or anxious. Vision is not always reliable throughout the day, so it’s best we let Henry have a well deserved break.
Nai is one of many adults with CVI sharing their lived experiences, and we’re learning so much about how CVI affects everyday life. This is why we must center CVI voices, so we continue to grow our understanding of CVI and inform research, assessment, and promising practices.
Research supports what individuals with CVI experience every day: chronic fatigue. There is a neurological and physiological reason why individuals with CVI become so easily fatigued. Each individual experience visual fatigue differently. It is a condition that must be carefully assessed and supported and it is not something that is typically assessed in a routine eye exam.
Examples of how visual fatigue manifests include:
The threshold to be able to process multiple items at once in CVI is much lower. Individuals with CVI have to work significantly harder when attempting the same visual tasks as their sighted peers. And often these tasks have to be adapted for individuals with CVI to have full visual access.
With an increased visual load, individuals with CVI have to grind it out, as opposed to having that instantaneous capture of information we see with a really efficient visual system.
Dr. Merabet
Envision how face blindness, visual fatigue, the impact of clutter, and other visual behaviors associated with CVI may manifest in these seven newly rendered images. Check out these examples of rendered images based on reports from children and adults living with CVI, the leading cause of childhood blindness and low vision.
Cerebral/Cortical Visual Impairment (CVI) is the leading cause of childhood blindness and low vision, yet it is alarmingly misunderstood and undiagnosed. CVI is a lifelong brain-based visual impairment, caused by damage to the brain’s visual pathways or visual processing areas. It’s usually diagnosed when abnormal visual responses can’t be attributed to eye problems alone.
People with CVI struggle with visual attention and visual recognition, resulting in a lack of access to the world around them. Some people see the world as distorted and unrecognizable. Others can focus but might struggle to understand what they see. A crowded setting, a hot day, or fatigue has the potential to make vision use nearly impossible.
Learn more about when to suspect CVI, what the diagnosis looks like, steps you can take after diagnosis, where you can find doctor in your area, and diagnosis stories from our communities.
