Ellen Mazel on the challenges and reasons for optimism around CVI

Mazel discusses CVI, the misperceptions around assessment and program planning, and explains the reasons we can expect visual improvement.

Photo portrait of Ellen Mazel

In 2002, Ellen Mazel had been working as a teacher of children with visual impairment (TVI) for more than two and a half decades. Yet for all her experience, she found with certain children her typical ocular intervention methods and assessment tools were proving ineffective.

“I had been using my bag of ocular tricks and it wasn’t working,” said Mazel. “Something was really different. The field was shifting with different kinds of children that had different kinds of visual needs.”

Around that time, she attended a seminar at Perkins School for the Blind about cortical/cerebral visual impairment (CVI). There, she learned people with CVI have normal or near-normal eye exams as the impairment is instead a brain-based visual disorder. She was fascinated to discover a different set of assessment criteria is required for CVI. Equipped with new information and techniques, she began to look at her student’s visual behaviors differently and found techniques learned at the seminar worked.

“It was like, why is this working?” she said. “I felt I needed to understand this better and figure out why these techniques were effective.”

Now more than 40 years into her career, Mazel has become a leader in the field, serving today as the Director of CVI Research and Development at the CVI Center at Perkins. Here, she shares some of her expertise about CVI, the misperceptions around assessment and program planning, and explains the reasons we can expect visual improvements in students with CVI.

How is working with kids who have CVI different from those with ocular impairment?

For children with ocular visual impairment, we understand the cause and the implication of the eye condition and work around those difficulties to provide access. For children with brain-based visual impairments, we must understand the cause to the best of our ability, identify the visual difficulties and put strategies and educational programming in place to improve visual recognition, the underlying issue. Effectively, what we’re trying to do for kids with CVI is to provide visual accessibility at the identified functioning level and then infuse supports across the day throughout their programming. This helps build visual recognition. We need a completely different set of criteria for not only assessment, but also for consistently and effectively used interventions. We also need to acknowledge that children with CVI are visually impaired and share the same need for systematic instruction for the missing visual information. The Expanded Core Curriculum is certainly an example of that.

Perhaps because it’s so different from an ocular impairment there’s a lot of misunderstanding around CVI. Can you break down what’s happening?

In the old days, you’d get the eye doctor’s report and understand where and what the problem was in the eye. You would do your functional vision assessment and put program planning in place. That was a nice, smooth trajectory. Now we’re getting clean eye reports, yet the children are obviously visually impaired. This creates confusion for doctors, educators and families.

What’s the result of this confusion?

The eye doctor will say, “there’s nothing wrong with the child’s eyes” and dismiss the child. The parents know something’s wrong with the way the child sees but can’t get a diagnosis of the problem. Without a diagnosis, the child begins school with no understanding of the impact of CVI on learning. Many do not believe the child has a visual impairment because the educational community also has limited knowledge of CVI. They mislabel children as “cognitively impaired,” “autistic” or as having “ADHD” when in fact the child lacks visual access. Their visual behaviors are not well understood. CVI is not well understood.

How can that disconnect be addressed?

The dynamic has shifted towards increased collaboration between the medical and educational communities. I might see a child who has the unique visual behaviors of CVI and I need to communicate that functional visual assessment to the eye doctor. We have to partner around CVI and share information between our disciplines for diagnosis and for understanding our patients and students. Otherwise, we’ll keep slipping into that old idea of vision as strictly an ocular issue and not thinking about it as possibly brain-based.

What are you, and Perkins, doing to bridge that gap?

Perkins has partnered with Dr. Lotfi Merabet, who is a renowned vision researcher at the Lab of Neuroplasticity, which is through Mass Eye and Ear at Harvard. Having Dr. Merabet talk about CVI in the medical community carries a lot of professional weight. That’s been a very, very good partnership and the beginning of the needed collaboration model.

We have some great partners here in the Boston area hospitals and have a wonderful collaboration with our own New England Eye Clinic at Perkins. Using three data points—ophthalmology report, low vision report of vision, the functional vision assessment of the child with CVI–we get a diagnosis and firmly identify clearly what both supports and interrupts visual attention and visual recognition. We also define strengths—those “survival skills” that the child uses to process the world. The information is shared with parents and the medical team for a fuller understanding of the child’s visual needs. Setting up systems for these partnerships is really going to serve kids better.

Switching gears, what drew you to CVI?

The whole idea of the brain fascinates me. When I was studying to become a TVI, they never talked about the brain. It just blows my mind, we didn’t think about how the eye and brain worked together for “vision.” I also think it is tremendously exciting that we might make a child’s vision work a little bit better. That’s a real possibility once we support visual attention and give that child the best opportunities to build visual understanding.

What’s your hope for the future as it relates to CVI?

My hope is we really change children’s visual recognition as much as possible. Anecdotally, I can tell you every child with CVI that I have served has made some improvements in their vision due to improved access. The recovery can be different for each child. I want professionals in the field to understand the possibility of visual improvement. I want visual considerations implemented throughout the child’s day in conjunction with compensatory skills for this improved visual access. My hope is everybody embraces building an understanding of CVI so every kid has the possibility of improvement in vision.

Learn How Perkins Can Help
Your child with CVI has the potential to improve his or her use of vision. Visit for more information and resources.

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