Bauer Lab: CVI Research

Research in CVI will help understand CVI, help with diagnosis of CVI and help us understand how to create access. Please consider helping!

The Bauer Lab
Massachusetts Eye and Ear
Harvard Medical School

Help answer important questions like:
-How does brain injury during early childhood impact long-term brain development?
-What is the link between early brain injury and Cerebral Visual Impairments (CVIs)?
-How do CVIs impact activity, participation, and quality of life?

Aged between 10 – 30 years old and have:
1) Evidence of an early developmental
brain injury, stroke, trauma, or preterm
birth (i.e. prior to 37 weeks gestation)
2) Visual acuity better than 20/100
3) A diagnosis or suspicion of cerebral (cortical) visual impairment (CVI)
We are also seeking volunteers with no history of brain injury or visual impairment to serve as controls.
Degree of participation depends on level of comfort of the individual, and may include:

  1. MRI scanning sessions (training and
  2. Computerized tests of visual perception
  3. Questionnaires
  4. Participation in all phases of the study is not mandatory, and total compensation is
    dependent upon degree of participation.

Contact information

For more information, please contact us at
(617) 573-3794 or through email

Perkins CVI: Collaboration for Change Conference

Perkins School for the Blind has a major initiative to create change in the awareness of CVI, the assessment of CVI, the educational programming for CVI, advocacy around CVI and the ever important, collaboration around CVI for parents, vision professionals, medical providers and people with CVI. Check out the robust lineup of speakers and topics at this conference being held on June 26-28, 2022 at the Revere Hotel in Boston, Massachusetts.

You will learn about the latest research around CVI. You will hear about a new assessment tool that educates teachers, walking them through assessment. You will hear about important considerations for educational programming. Importantly, you will hear from individuals with CVI and parent of students with CVI who drive all efforts the work around CVI.

Hope to see you there!

Accessible Literacy: Controlling Background Clutter? Don’t Stop There!

So often when people think about making accessible books for children with CVI, they enthusiastically share ideas about removing the background clutter and complexity. They set off to create an accessible book. The trouble is that they stop at removing clutter and complexity but still leave the book inaccessible to the child.

Any materials created for children with CVI simply must consider all accessibility needs.

Literacy materials created should match all the assessment results both for ocular needs and for CVI needs. They need to incorporate the child’s compensatory skills as a support for visual skills. Materials that appear in books need to be meaningful and experienced by the child. If the child has no experience with the concept represented in the book, they will not understand or relate to the items or with the story. They will not remember the aspects presented in the book. The book should be based in the child’s natural routines of day to day life for the optimal building of visual recognition. Perhaps most importantly, they must appear in the correct accessible Form.

Form Accessibility

Any literacy material must consider the accessibility of the Form.  The form is the media understood by the child. The book creator must assess the form understood by the child in order to develop a book matched to the child’s perceivable media form. Is the child at the level of looking at and recognizing only 3D real items? It the child able to perceive and understand real photographs? Can the child understand if the item is multi-colored or does that make them think they are seeing several separate items of different colors?

If the child is only perceiving 3D items, 2D is inaccessible. No flat book by itself can provide access to literacy. It must be supported in several ways:

  • Make the book yourself. Use items already within the child’s visual world that occur in the child’s natural routines. These are the most likely to be recognized.
  • For students with fragile visual attention and fragile visual recognition, provide a storybox of real items to be explored using all the senses.  The child can look at the item, look at the item in all perspectives, feel the item and make sound with the item.
  • Photographs that appear in the Powerpoint book should use photographs of the exact experienced and recognized storybox items since it it likely that the child will still be coding items by color.

Compensatory Skills

Auditory: Separately delivered verbal information before and after the child looks.

Create some auditory interest by using the Powerpoint audio feature in the literacy creation. Capitalize on the auditory skills to give support to what is presented visually. (Example: Dog barking when the dog appears gives support for the visual image of the dog.)


Support visual understanding using tactile exploration of shape and function. Base the literacy material on real experienced items tactilely explored for understanding.

Impact of Light

Making Powerpoint books allows you to provides backlighting that can be beneficial for our students with CVI. It can reduce visual fatigue. The level of lighting can be adjusted if the child is sensitive to light. That backlighting helps to improve visual attention and helps to bring attention the the details of objects. It can also improve visual recognition.

Impact of Motion

Making Powerpoint books can allow you to create embedded motion, if desired, using the ”Animation” feature. Slower, predictable motion can help draw and sustain visual attention.

Response Interval

Unlike a book that needs to be held, the screen-based book is stable and remains available for as long as the child needs. It allows the literacy material to appear for any length of time that the student needs to visually locate, sustain gaze and understand what is on the screen. This allows you or the child to have the ability to control the speed of the activity.

Visual field

Any learning materials including literacy materials must consider placement in the child’s best visual fields. These are often raised positions that bring materials out of problematic lower visual fields using slantboards or raised screens. The stable nature of slantboards and raised screens provides consistent positioning and stable presentations.

More about Crowding/Clutter/Spacing and Object Arrangement

There is more clutter/crowding and spacing needs than just removing the background. The ability to reduce all clutter also considers spacing items for discrimination and using solid, saturated, one colored items for ease of visual recognition. To capitalize on predictability, objects on the page should be in a consistent arrangement such as a linear arrangement or an arrangement in a grid so the child can scan each page space on every single page to take in the whole scene.

Access to People

Consideration of the access to faces is an important consideration for literacy accessibility. With fragile visual attention to real faces, there is very, very fragile facial recognition of real people encountered in life. If children can not visually attend and can not recognize real people around them, flat photographs of real people are completely inaccessible and meaningless. If photographs of people must be used, code each person by the color of their clothing so children can discriminate the image effectively using that support of color.  

Sensory integration Using Vision

Due to difficulties with simultaneously presented visual and auditory information, create a book or a present a book considering a separation of the visual from the auditory components of the literacy material. Verbally read the story first then present the visual images. Provide verbal labeling of the objects on the screen. Provide labeling of actions on the screen.

Impact of Color

Consider color in accessible literacy. Solid one-colored items presented with be more easily seen as one complete item. The one color holds the image together for the best visual recognition. Using images in the book using vastly different colors will allow for fast identification and discrimination. Color can be applied to distinct areas to draw visual attention.

Provide black non-complex backgrounds for contrast and to reduce complexity.

Visual Curiosity

The use of Powerpoint books provide literacy access in near space where it is most perceived.

Because the child often lacks the incidental information, experiences that the child has in real life should be the basis of literacy. If the subject of the book is a cat, that child needs extended learning about cats. Where to cats live? What and how do they eat? What do their babies look like? How do they move? All this is information that most children learn by just watching. Our children with CVI need that learning access considered and delivered.

There are accessibility needs beyond removing the background! Consider all the assessment results when you create accessible books!

Assessing Needs Around Light

When first learning about CVI, I only was taught to focus on the child’s visual attention to light. This included looking at the visual attention to environmental light and to looking at the visual attention to lighted objects.  

In the hundreds of assessments that I have done since 2002, parents and students have expanded my understanding of the multiple ways light can impact a child with CVI. Here is what I have learned so far from listening to those important voices, voices of people living with CVI.

Some children do have increased attention to environmental light: to lights in the ceiling and lateral light provided by lamps. Some have attention to windows and doors (which also tend to have the element of motion: moving leaves on trees, cars moving, people moving down hallways.) Some children have greater attention to lighted toys or to technology like iPads, iPhones and backlighted devices.

Some children have light sensitivities. They avoid light especially if it is too bright for them. Different spectrums of light can be bothersome such as the brighter sunlight outdoors. Certain light bulb spectral qualities are bothersome. Some children don’t like devices with light when it is too bright and they prefer dim backlighting. They report that backlighting eliminates their ability to see any objects placed on that backlighting.

Some children have difficulties with changing light levels. They stop at the entrance of rooms that are darker or at the entrance of rooms that are lighter. This makes leaving a bright room and entering a dark room or coming out of a dark room into a bright room very difficult. They often need to stop and adjust before moving forward into that new environmental light level.

Some children will avoid crossing reflected light on the floor or avoid and fear shadows on the ground.

In assessing a child with CVI, these are the multiple impacts we must consider since all have an impact on visual functioning.

Assessment of Light:

  • For attention to light, we can eliminate light that is distracting to look at the visual attention to objects. For attention to light, we can see the impact of visual attention when using lighted objects vs non-lighted objects.
  • For light sensitivities, we can interview parents and students for information and, in direct assessment. look at the child’s reactions to various light intensities.
  • For reactions with changing light levels, we can ask parents and students but also observe the visual behavior in various environments with changing light level changes: entering a dark auditorium from a bright hallway or leaving a room to go outside in bright sunlight.
  • We can assess the benefit of backlighting and ask ourselves: Does backlighting speed visual attention to the object or picture on it? Does backlighting allow the child to look at the object of picture longer? Does backlighting change the visually guidance of the upper limbs with improved and more accurate reaching using vision? Does backlighting improve reading comprehension, speed and sustained reading abilities? Does backlighting aid the child’s visual recognition of objects and pictures?
  • We can watch a child’s reactions to shadows and reflected light on the floor. Do they stop and test with their foot? Do they walk around it? Are they fearful?

It is so important to remember that the brain of a child with CVI is unique. When that brain is impacted, we must be ready to learn exactly how that effects the child’s visual attention to and visual recognition for learning.

Think about how light might draws visual attention but don’t forget that very important consideration of light sensitivities, the difficulty with changing light levels, how light on the floor impacts navigation and whether certain backlighted light levels help or hinder learning.

CVI Advocacy: Modeling Skills

One of the core needs for a child with a visual impairment is advocacy. It is an essential component of the Expanded Core Curriculum for learners with visual impairments. Children need to understand CVI (the cause of of their visual difficulties), be able to name that specific visual behavior difficulty and be able to present concrete solutions. This is especially true for children with CVI. CVI is a misunderstood, often invisible visual impairment. Advocacy by the child becomes much more necessary to ensure visual accessibility in learning and life.

Some children with CVI are clearly visually impaired due to their very limited visual attention to the objects and people around them. They are impacted by clutter, motion, crowding, difficulty with faster visual tasks, difficulty in noisy places, difficulty using eye/hand or eye/foot visually guided motor skills, difficulty looking at or visually identifying objects and people and difficulty with any 2D forms. The general public can clearly “see” their version of CVI. Adults that do not understand visual neuroplasticity, the possible capacity to improve visual skills, see this severe visual impairment and never present objects visually. They tend to bypass vision to use other compensatory skills. For the adult that does understand CVI, modeling advocacy builds skills for the child across the day, across different environments and across the child’s lifetime.  To build visual attention the adult need to model: “Joe: Here is a ball. You have CVI so I will hold it close, at eye level, move it slightly until you can see this round, red ball.” (Hold until visual attention it gained). “That was great Joe. I will let you feel the round ball (present until the hands and fully explore). “Joe: I will show this round, red ball again (Hold until visual attention is gained).  Just teaching the child to ask “Can I see it” and “What does it look like?” reminds the adult to provide visual access and to provide a verbal description.

Some children with CVI have better visual attention but lack visual recognition. These are the children who might not seem visually impaired at all. They look at objects and people but looking does not mean they understand what they see. They are impacted by clutter, motion, crowding, difficulty identifying newer things, difficulty with faster visual tasks, difficulty in noisy places, with identifying people, difficulty stepping and reaching accurately, and difficulty with more symbolic forms (like cartoon pictures that don’t look like the real object).

Their advocacy helps them understand their version of CVI, empowers them and reduces frustration, reduces anxiety and reduces “CVI Meltdowns”.

I used to work with a young student with very good visual attention. Most people seeing her would not understand her version of CVI. She had a “invisible visual impairment”. She looked at objects and some people but looking did not mean she understood what she was seeing. She was greatly impacted by motion, clutter and crowding especially if there was also noise.  If she was in a hallway with more than 3 people, talking and moving, she became anxious and afraid and the crying, lashing out CVI Meltdown would begin.

Seeing the student’s escalating anxiety, knowledgeable staff successfully modeled:

“This hallway is cluttered. Because of your CVI, clutter and motion are difficult. To solve this, you can ask to leave early before the bell rings or take the alternative route using another hallway. Which would you like to do?”

This simple advocacy modeling identified the problem, taught the child about her CVI and gave solutions to the child. Her anxiety in hallways reduced and CVI Meltdowns almost disappeared. 

Adults must understand CVI in order to teach advocacy effectively. Start early and providing modeled advocacy often gives children with the language and advocacy skills to ensure visual accessibility.

Cathy Williams: Harvard Distinguished Lecture Series

Tune in on May 20th 4:00 Boston time for Cathy Williams lecture on CVI. This is part of the Distinguished Lecture Series at Harvard.

Her work focuses on pediatric vision, and most recently on CVI and screening for vision-issues in school age and preschool- age children.

Zoom link: ID: 98933084874
Password: 739616​

Building Visual Recognition

Over the years, I have begun to think about learners with CVI in terms of visual accessibility with two distinctly different sets of visual skills: Visual Attention and Visual Recognition. When we understand the child’s abilities in these two areas, we can understand how accessible their visual world is and how reliance on compensatory skills is so essential for educational programming.

Visual attention is the precursor to any visual recognition. It must be understood that a child simply can’t have visual recognition (understanding what they see) without visual attention (actually looking, shifting to visual elements and seeing details).  Both visually attending and sustaining that attention are essential first steps before any visual recognition can develop. Check out Jeremy Wolfe’s work on visual attention in his Visual Attention Harvard lab.

When thinking about visual attention in assessment, I am looking at overall visual attention.

  • How often does the child look?
  • What kinds of things do children look at?
  • What is the length of time that children can hold that attention on the object?
  • It that length of time enough for children to see the details and feature of that item beyond just attending to movement, light or color properties?
  • When they look, do their eyes shift to the elements of objects or pictures?
  • What is the child’s visual curiosity for the world around them?

When thinking about visual recognition in assessment, that understanding of the visual attention skills is vital. Visual recognition requires:

  • Frequent and repeated looking
  • Sustained looking
  • Looking with the ability to shift central gaze to all parts of the items
  • Recognition of objects outside context. (Is the spoon recognized as a spoon without the child being told it is time for lunch, without being in the feeding area, without food smells, the bib cueing). 

When children are extremely impacted by CVI, there is simply no recognition because the ability to attend is so very fragile. There is no real visual recognition but isolated attention to certain types of color, motion and light. They may look as if they have “favorites” but really any object of that color, with motion and with light gets the same response. There is no recognition of the object itself.

If you don’t look at items, or when you so look, you don’t look long enough to understand, you don’t shift to the visual elements, the chance of building that visual library is at great risk. It is this visual attention that becomes our focus for creating accessibility.

“Wagon Wheel” Search

I just love this strategy proposed on CVI Scotland!. We know many children with cortical/cerebral visual impairment (CVI) have visual field differences that we must consider in educational programming. Teaching this methodical search strategy will help create greater access to the whole visual scene whether the child has upper, lower, left or right visual field differences. I have used it with great success!

The Importance of Predictability: Seeing What You Expect to See

With no well established visual attention, there will be limited visual recognition if any. The “visual library” is sparse due to the inability to look and shift attention to the parts of the item for the details of that item. For children with CVI who have limited visual attention, there may be visual attention to color, light or motion, but we can not assume this is visual recognition.

To assess visual recognition for these children who briefly attend to “favorite toys” that are bright colors, lighted or moving, we must be very clearly diagnostic about what we are observing. Is it only visual attention to color, light or motion or some level of recognition?


If you think the child attend to and recognizes the red stuffed dog, present that and record the reaction. Do they smile or reach excited towards it? Now present another red toy of a similar size. If the reaction is the same, it is likely that child is heavily coding his or her world by using color not recognizing that item by shape or detail. The object itself has no meaning. It is a just a red “thing”.

Our goal for students with such limited visual attention is to create environments that support visual attention by controlling distracting light, noise, clutter and motion. We foster that visual attention and strive to create object meaning, object recognition.

To create meaning and to foster visual recognition, we want to create a predictable world where the same objects are used in a meaningful routine. In this meaningful routine, the repetitive use of the same objects in combination with the smells, tastes, tactile input and sounds clue the child’s understanding and therefore provide access to the visual information connected to meaning. It is this predictability in meaningful contexts that allow our children with CVI to begin the visual recognition journey and to begin to build that visual library.

It is no surprise that when we provide the adaptations to the environment to foster visual attention, most children begin to recognize predictable items in the meaningful routines of mealtime. Mealtimes happen predictably three or more times per day. Parents report cups, bottles and spoons as the first kinds of recognized items. If you use the same mealtime objects with a child in a predictable and repeated routine such as mealtime, the child hears language about eating (auditory), smells the cooking or preparation of food in the context of the kitchen (context and smell), sits down in the highchair or dining chair (tactile and proprioception), and feels the bib being placed on (tactile). Those visual materials in context and with the other sensory information give visual meaning. It is no wonder these items are the starting points for visual recognition skills.