Accessibility in digital documents is not optional — it is a legal requirement in many countries (under laws like the ADA and Section 508 in the US) and an ethical obligation everywhere. When an educator distributes a document, they have a responsibility to ensure every student can read it.
Yet, one of the most frequently overlooked accessibility failures in STEM education is math equations embedded as images in Word documents.
On Reddit's accessibility and education communities, this issue comes up repeatedly. A visually impaired student receives a syllabus, a homework assignment, or a study guide where every equation is a small screenshot. When their screen reader reaches the equation, it simply skips over it, or worse, just reads the word "image" with no further context. The student is left entirely in the dark about the mathematical content of the lesson.
Why Image-Based Equations Are an Accessibility Disaster
When an equation is embedded as an image (a PNG, JPEG, GIF, or EMF file) in a Word document, it creates an impenetrable barrier for assistive technologies:
- Screen readers cannot parse pixels: Software like JAWS, NVDA, or Apple's VoiceOver cannot read text that is baked into an image. Without underlying text data, the equation simply does not exist to the software.
- Alt text is insufficient for complex math: While authors can theoretically add "alt text" (alternative text descriptions) to images, very few actually do. Furthermore, describing complex mathematics in plain text is notoriously difficult. How do you clearly and unambiguously describe a double integral with bounds, containing a complex fraction with Greek letters, using only a flat string of words?
- Magnification distorts the image: Students with low vision who use screen magnifiers rely on crisp, high-contrast text. When they zoom in on an image-based equation, the pixels stretch, becoming blurry, artifact-heavy, and unreadable.
- Braille displays cannot render it: Refreshable Braille displays rely on structured text data to raise and lower pins. They have no mechanism for interpreting a raster image.
- Color contrast cannot be adjusted: Many students require specific color profiles (like high-contrast yellow on black) to read comfortably. Word can adjust native text to match these profiles, but it cannot change the colors inside a static image.
The Solution: Native Word Equation Objects (OMML)
The solution is surprisingly simple, yet rarely implemented consistently: equations must be formatted as native Word equation objects using Microsoft's Office Math Markup Language (OMML).
When an equation is stored as an OMML object, it is treated as structured mathematical data, not a picture. This unlocks full accessibility:
- Screen readers like JAWS and NVDA interface directly with Microsoft's UI Automation API to read the equation aloud correctly, interpreting the hierarchy of fractions, exponents, roots, and operators.
- The equation renders as vector data, meaning it scales infinitely. A student can zoom to 500% and the equation remains perfectly crisp.
- The colors invert automatically when the user switches to a high-contrast theme.
- The equation is fully navigable. A screen reader user can step through the equation character by character to understand complex notation.
How Inaccessible Equations End Up in Documents
Educators rarely make documents inaccessible on purpose. Image-based equations usually end up in documents due to flawed workflows and a lack of awareness:
- Copy-pasting from PDFs: This is the number one culprit. When a teacher copies an equation from a PDF textbook and pastes it into Word, the operating system's clipboard almost always transfers it as a bitmap image.
- Using generic PDF converters: When converting a PDF to Word using standard tools (like Google Docs or basic online converters), the software cannot understand the math, so it takes a screenshot of the equation area and pastes it into the output document as an image.
- Taking screenshots: The Snipping Tool or Mac Screenshot utility is often used to grab equations from web pages, slides, or older documents to paste into new ones.
- Using legacy equation editors: Some older third-party equation editors (like older versions of MathType) export equations as OLE objects or EMF images that modern screen readers struggle with.
How to Fix It: Making Your Documents Accessible
If you have a document full of image-based equations, you need to replace them with native OMML objects. Depending on your situation, here are the best approaches:
Approach 1: Use a Math-Aware PDF Converter
If you are starting from a PDF and converting it to Word, do not use a generic converter. Generic converters produce the very image-based equations that cause accessibility failures.
Instead, use a specialized tool like MathToWord's Math PDF to Word Converter. This AI-powered engine is specifically designed to recognize mathematical structures and reconstruct them as native OMML objects in the output DOCX file. By using the right tool at the start of your workflow, the resulting document is accessible by default.
Approach 2: Convert Individual Equation Images
If you already have a Word document containing image-based equations, you can replace them one by one. Take a screenshot of the equation image, upload it to the Equation to Word Converter, and copy the resulting native Word equation object. Delete the image from your document and paste the native equation in its place.
While this takes time, it is significantly faster than retyping complex equations manually from scratch.
Approach 3: Retype Simple Equations
For very simple inline equations (like x² + y² = z²), the fastest method is often simply deleting the image and retyping it using Word's built-in equation editor (press Alt + = to open it).
Testing Your Documents for Accessibility
You do not need to be an accessibility expert or own expensive screen reading software to verify that your equations are accessible. You can perform a simple visual test:
- Open your Word document.
- Double-click on an equation.
- Pass: If clicking the equation places a blue bounding box around it, reveals a tab labeled "Equation" in the ribbon, and allows you to place your text cursor between the math symbols, it is a native OMML object and is accessible.
- Fail: If clicking the equation places a box with eight resize handles on the corners and edges, and the "Picture Format" tab appears in the ribbon, it is an image. It is entirely inaccessible to a screen reader.
Accessibility Is Not Extra Work
A common misconception is that making documents accessible requires double the work. In reality, accessible documents are simply properly formatted documents. When you use native equation objects instead of images, your document becomes accessible to screen readers, scales cleanly for printing, is editable for future updates, and has a smaller file size. There are zero downsides.
Making STEM education accessible starts with the fundamental building blocks of the curriculum: the equations. If your current documents rely on image-based equations, take the time to convert them. Use the Math PDF to Word Converter for bulk conversion, or the Equation to Word Converter for individual fixes. By using native Word equations, you ensure that every student, regardless of their visual ability, has equal access to the material. Explore all our free conversion tools.