Teaching Letter and Number Identification to Students with CVI

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Did you know someone can have perfectly healthy eyes but struggle to see? 

Cortical/cerebral visual impairment (CVI) is a brain-based visual impairment. It is also the leading cause of visual impairment in children. Our eyes and brain have to work together to receive visual information. For students with CVI, their eyes may be in good health, but the visual pathways or visual processing parts of their brains are ineffective.

Students with CVI require unique adaptations to learn about the world around them. The strategies outlined in this article can help you teach individuals with CVI to identify letters and numbers visually.

Prerequisite Skills

Before working on print letter and number identification skills with a student with CVI, there are many prerequisite skills to consider. Every individual with CVI is different; a student can begin identifying letters and numbers before mastering prerequisite skills. However, most students benefit from mastering these skills before being asked to match, write, or visually identify letters or numbers.

For all the skills listed below, it is best to select objects familiar to the student, do not produce sound, and are a single bright color. Students may visually attend to specific colors more than others. It is also important to present materials against a plain background and in the visual field where they see best. For students who benefit from movement, light sources or objects can be shaken, and images or shapes on a backlit display can be presented with animation features that have them wiggle or spin. 

The Prerequisite Skills are as Follows:

  • Visually attending to a stationary, light-up object inside a dark room
  • Visually attending to a stationary object illuminated with spotlighting (i.e., a flashlight or other targeted light source shining directly on it) or placed onto a lightbox
  • Visual tracking of a slow-moving, light-up object inside a dark room
  • Visual tracking of a slow-moving object illuminated with spotlighting, placed onto a lightbox, or presented against a plain background
  • Matching a given familiar object to a field of 2-3 familiar objects illuminated with spotlighting, placed onto a lightbox, or presented against a plain background
  • Matching a photograph on a backlit display (e.g., iPad) to a field of 2-3 familiar objects illuminated with spotlighting, placed onto a lightbox, or presented against a plain background
  • Matching an image of a shape on a backlit display to a field of 2-3 shapes—These shapes may be solid, illuminated with spotlighting, or presented against a plain background. They may also be transparent and presented on a lightbox with a ledge.
  • Sorting objects into two groups by shape or color—These objects and containers may again be solid and illuminated with spotlighting or presented against a plain background. They may also be transparent and presented on a lightbox. In either case, I usually begin by giving students only 1 or 2 items to sort at a time and slowly increase the number of items.

Expressively identifying 2D shapes one at a time as images presented on a backlit display, solid shapes attached with Velcro to a black felt board, or transparent shapes shown on a lightbox with a ledge

The first photo shows a transparent yellow square and circle sitting on a lightbox with a ledge in a dark room. A yellow circle with a black background displayed on an iPad appears to float behind the lightbox. The iPad is in a black case on top of a black box with a black felt tri-fold board behind it. All of these black materials become invisible in a dark room.
The second photo shows red and yellow transparent shapes ready to be sorted into a transparent red bowl or a transparent yellow bowl lying flat on a lightbox.

Image Descriptions: The first photo shows a transparent yellow square and circle sitting on a lightbox with a ledge in a dark room. A yellow circle with a black background displayed on an iPad appears to float behind the lightbox. The iPad is in a black case on top of a black box with a black felt tri-fold board behind it. All of these black materials become invisible in a dark room. The second photo shows red and yellow transparent shapes ready to be sorted into a transparent red bowl or a transparent yellow bowl lying flat on a lightbox.

Matching Letters and Numbers

Once a student has shown mastery of prerequisite skills, they are ready to move on to matching print letters and numbers. One way to do this is by presenting a letter or number to the student on a backlit display and having them match it to a field of 2-3 number cards on a black felt board or 2-3 transparent letters presented on a lightbox with a ledge. I usually begin by focusing on the letters in the student’s name and the numbers that represent their age and the age of a close friend or sibling.

If you have an iPad, another great tool is the Bubbly app developed by UNC Chapel Hill. In addition to helping students identify uppercase and lowercase letters in print, this app can help students visually identify CVC (consonant-vowel-consonant) and high-frequency words. I love how you can customize the outline to the preferred color of each student. 

Red, transparent, capital letters X, B, and T sitting on a lightbox with a ledge in a dark room. A red X with a black background displayed on an iPad appears to float behind the lightbox.
screenshot from the Bubbly app with three white capital letters B, T, and X on one side and one red outline of an X on the right.
Screenshot of the Bubbly app showing the enlarged letter and confetti that appears after you drag the correct letter into the bubble. 

Image Description: The first photo shows red, transparent, capital letters X, B, and T sitting on a lightbox with a ledge in a dark room. A red X with a black background displayed on an iPad appears to float behind the lightbox. The second photo is a screenshot from the Bubbly app with three white capital letters B, T, and X on one side and one red outline of an X on the right. The third photo shows a screenshot of the Bubbly app showing the enlarged letter and confetti that appears after you drag the correct letter into the bubble. 

Writing Letters and Numbers

Some students can only begin identifying letters and numbers after learning to write them. This may be because learning to write naturally lends itself to focusing on the salient features of each letter or numeral. Like with matching, I usually start with the letters in the student’s name and the number representing their age and the age of a close friend or sibling.

One way to work on writing is by using a black outline of a letter or number to be traced on a lightbox using an expo marker in a student’s preferred color. 

Students may also enjoy using transparent building pieces to build letters or numbers on a lightbox. This is another great way to incorporate light and color and also allows students to physically feel the lines and curves you are talking about when you describe each letter and number. 

Black outline of the capital letter “L” on a lightbox in a dark room.
Two transparent, orange lines interlocking to create a lowercase letter “v” on a lightbox in a dark room. 

Image Descriptions: The first photo is of a black outline of the capital letter “L” on a lightbox in a dark room. The second photo shows two transparent, orange lines interlocking to create a lowercase letter “v” on a lightbox in a dark room. 

If you have an iPad, the Glow Draw or Writing Wizard app are other great customizable tools for working on writing.

screenshot of the numbers 1, 2, and 3 written with the Glow Draw app.
screenshot of writing the capital letter “S” on the Writing Wizard app. It is customized to have a black background.

Image Descriptions: The first photo is a screenshot of the numbers 1, 2, and 3 written with the Glow Draw app. The second photo is a screenshot of writing the capital letter “S” on the Writing Wizard app. It is customized to have a black background.

Identifying Letters and Numbers Receptively

Working on identifying letters and numbers receptively means asking students to point to a specific letter or number from a field of more than one choice.

I work with students on this skill by using an expo marker in the student’s preferred color(s) to write 2-4 letters and numbers on a whiteboard. Using letter magnets is another good option if the whiteboard is magnetic and I have magnets in the student’s preferred color(s). 

If you have an iPad, you can also use Google Slides or PowerPoint to present the student with a field of letters or numbers in their preferred color to choose from. If your student does well with visual matching letters in a wide range of colors, the Alphabet ABC iPad app may be another good option. This app uses a white background and can present 1-10 letters at a time. I usually begin with a field of 2-3 letters and slowly increase the number of choices.

screenshot of red letters T and Z on an iPad.
screenshot from the Alphabet ABC iPad app showing a field of four letters in different colors: B, A, E, and V. 

Image Descriptions: The first image is a screenshot of red letters T and Z on an iPad. The second image is a screenshot from the Alphabet ABC iPad app showing a field of four letters in different colors: B, A, E, and V. 

Identifying Letters and Numbers Expressively

Working on identifying letters and numbers expressively means asking students to identify a specific letter or number shown to them in isolation. 

Show students a single letter or number using transparent materials on a lightbox, a slide on a backlit display, a magnet on a whiteboard, or markers on a whiteboard.

Braille and Dual-Media Instruction for Students with CVI 

For some students with CVI and/or additional ocular visual impairment that impacts their physical eyes, braille may be an appropriate primary or secondary literary medium. The results of an LMA should be used to determine the best literary medium for all students who are blind or low vision, including CVI. 

I love using a light-up braille cell when teaching the concepts of top, middle, and bottom and left and right in relation to a braille cell to students with low vision or CVI. For some of my students with CVI, I have added color by using double-sided tape and cellophane sheets in a student’s preferred color that I then cut and placed over each tap light. Another option is a Hop-A-Dot mat from the American Printing House for the Blind. It comes in blue or red with yellow dots. Depending on the student, it may work best if hung or attached to a wall instead of being presented on the floor.

enlarged representation of a braille cell created using a small black chalkboard stand and six circular tap lights. It sits on a black box, and a black trifold board sits behind it.
large floor mat, a Hop-A-Dot, representing a braille cell. It has six blue squares made of foam that interlock. Inside each square is one large removable yellow foam circle with a number 1-6 on it.

Image Descriptions: The first photo is of an enlarged representation of a braille cell created using a small black chalkboard stand and six circular tap lights. It sits on a black box, and a black trifold board sits behind it. The second photo shows a large floor mat, a Hop-A-Dot, representing a braille cell. It has six blue squares made of foam that interlock. Inside each square is one large removable yellow foam circle with a number 1-6 on it.

Closing Remarks 

When planning instruction for individuals with CVI, there is no list of strategies that are “one size fits all.” However, I hope the methods listed in this article help you and your child’s team discover the best strategies for your unique student.

Additional Resources

  • CVI Now is a phenomenal resource for learning more about CVI. 
  • CVI Book Nook is another fantastic resource with free books for teaching letter and number identification that can be printed or shown to your student on an iPad or other backlit display. The books even include written scripts for describing the salient features of each letter or numeral.
  • You can also follow me on Instagram @prektvi to learn more about how to support the needs of students who are blind or low vision.