Digital Accessibility for Students With Visual Impairments: Start by Checking the Alt Text

Students with visual impairments listen to their materials through a screen reader. And yet a PDF a teacher built with real care is often read out by the screen reader as the single word "image." The key information inside the picture disappears wholesale. Accessibility is decided less by expensive equipment than by small habits at the moment the material is made. AI helps generate alt text, but the review is a person's job.

What it takes for a material to work with a screen reader

A screen reader reads along the structure of the document. With no structure, it gets lost.

• Alt text: Attach a sentence describing the content to every image. Write it as "a graph showing temperature rising from March through June" rather than "graph 1."
• Heading structure: Assign titles and subheadings as actual heading levels rather than as formatting, so the screen reader can navigate them like a table of contents.
• Reading order: Make sure the reading order does not get tangled in a two-column layout.
• Table header rows: A table needs its header row specified for the meaning of each cell to come through.

A well-made accessible material is not only for students with visual impairments. Material with a clear structure is easier for every student to read.

Students with low vision need a different prescription

The single term "visual impairment" bundles total blindness and low vision together, but the support each one needs is quite different. Where a student who is totally blind relies on a screen reader, for a student with low vision it is often more effective to make the most of the vision they still have. Here the essentials are enlarged text, high-contrast color combinations, bold typefaces, and adjustable zoom. With the same material, some students find black text on white comfortable, while others can only read it as yellow text on black. So rather than fixing the material in one form, it is better to build it so students can adjust the color, size, and zoom themselves. Use an original large enough that images do not break apart when magnified in close, and for paper materials, prepare an enlarged printout in advance. The point is to fit not the diagnosis but how that particular student actually sees. The care to differentiate the prescription even within the same category is what decides the quality of your accessibility.

Building and reviewing

1. Generate a first draft of image alt text with AI, but always review whether it fits the subject-matter context. Automatic descriptions easily miss the point.
2. Formulas and diagrams are hard to convey when read aloud, so write out a spelled-out explanation alongside them.
3. Check the finished material by listening to it through a screen reader yourself. Problems are hard to find with your eyes alone.
4. Do not distinguish information by color alone (students with color vision deficiency need to be considered too).
5. Review assessment materials more strictly so that no one loses points because of accessibility.

Key takeaways

Digital accessibility for students with visual impairments starts with the habits you bring to making materials. Take care of the alt text, heading structure, reading order, and table header rows, and the screen reader conveys the content whole. AI will hand you a quick first draft of alt text, but the subject-matter review has to be done by a person, and listening through a screen reader yourself is the surest way to finish.