How CVI impacts learning math

$A young boy who has CVI moves multicolored blocks around on top of a light box.$

From Matt Teitjen, Nai Y., and Rachel Bennett, authors of book-in-development CVI Ally: A collaboration resource for people with brain-based blindness and other forms of visual neurodiversity, and their teams

CVI impacts access to math concepts, materials, and skill development. Every person with CVI will have their own experience with math. Still, there are some common ways CVI affects visual access to math. This includes everyday experiences that build basic skills.

Visual recognition

Many with CVI have difficulty recognizing two dimensional information, including numbers, symbols, operation signs, shapes, array of lines, and letters. Much of math instruction is rendered in 2D, making access for many with CVI very difficult.

Impact of visual clutter and simultaneous visual information

Many with CVI have difficulty processing visual clutter and simultaneous visual information. Some may recognize individual numbers but struggle with multi-digit numbers due to too much visual information. Often math problems and equations are presented on worksheets with many others. This can be too much visual information, clutter, and crowding for a person with CVI to process and see. It can be hard to see all items in a set or a row of objects for 1:1 counting. In a diagram, chart, or x and y axis, it can be difficult to visually process all of that information at once. Some with CVI might only see one part, number, letter, or line at a time, and can’t make sense of the whole and how all elements relate to one another.

Visual-spatial processing

Math includes visual-spatial processing demands. It requires students to organize visual space and to process the relationships between the elements in that space. Difficulty with visual-spatial processing is closely related to challenges with seeing multiple things at once. If a student with CVI cannot see all of the elements in a math equation, shape, or diagram, then they cannot begin to judge the spatial relationships between these elements.

For example, a student who can only see one number at a time on a number line, will likely have difficulty understanding how the numbers relate to each other spatially from left to right. Similarly, if a person can only see two or three numbers at a time in a multi-digit addition problem, then they are unlikely to be able to keep track of the place value columns in order to add the correct numbers or place numbers in the correct column when carrying over. Another example is when a word problem or list of numbers contains a lot of visual information—part of solving the math involves organizing it into rows, columns, or creating visual and spatial relationships to understand it.

It can be difficult for some with CVI to visualize these relationships. Even when a student with CVI can see all of the information at once, it can be hard to approach a math equation in an organized way (left to right, top to bottom), see how numbers relate to each other in columns or on a graph, or compare lengths of lines or judge angles.

Counting is a visual spatial task that requires us to keep track of what we counted and what is left. Our brains apply a visual-spatial tag on items we’ve already counted, so we don’t recount them. According to Stanislas Dehaene from The Number Sense (2010), people who have difficulty processing simultaneous visual information had difficulty with applying these tags as they counted.

Incidental learning

A lot of early math learning happens naturally, just by watching the world. This is called incidental learning—when children pick up ideas by observing everyday things, like how many crackers are on a plate, what happens when you take one away, or how toys are lined up in a row.

By the time children reach kindergarten, they’ve usually had tens of thousands of hours of visual observation. They’ve seen things added, taken away, compared, and grouped. So when we introduce numerals and symbols in school, we’re building on what they’ve already internalized through these early visual experiences. The numbers and symbols are really just abstract ways to describe ideas they already understand, like quantity, order, and relationships between objects.

But many children with CVI don’t have full access to incidental learning. They might not see someone add or subtract objects, or notice when one group has more than another. That means they may start school without the same foundation, because those early, everyday opportunities to build number sense were not fully accessible. When thousands of hours of observation are reduced or missing, it can deeply affect how math concepts are understood. Accessible instruction and materials can support learning in new ways.

Visualization

Some with CVI have difficulty with visualization, or creating imagery in the mind’s eye. Most people rely heavily on the ability to visualize when performing mathematics tasks. When most people think about numbers and their relationship to one another, when they add and subtract, and perform higher level mathematics tasks, they are doing so using a visual spatial number line. Some types of math require us to hold, rotate, and manipulate a shape or other concept in our mind’s eye. Word problems also require a great deal of visualization. Think of classic word problems like two trains leaving two different cities at the same time, or how many cubic yards of turf would it take to cover a football field. Such word problems require a level of internal visualization that some people with CVI may not have access to. Some with CVI have success when visual, tactile, or kinesthetic models are provided for them in place of an internal visual one.

Make no mistake: all students with CVI can become problem solvers and build math skills. An assessment-driven and student-centered approach is critical for instruction and learning. In order to approach math from a strength-based perspective, we must deeply understand the student’s individualized needs along with how to implement systematic math instruction. We must explore how multiple strategies, interventions, and multisensory learning unlock access to building math skills.