When adding images to your teaching resources, it is important to add a text description (known as ALT text) so that visually impaired users can still understand what is being shown.
Developed by The DIAGRAM Center (Digital Image And Graphic Resources for Accessible Materials), a Benetech Global Literacy initiative, the Poet Training Tool is a web-based image description resource that helps people learn when and how to describe various types of images frequently found in educational books. Users of this tool have access to best practice guidelines and hands-on exercises that help cultivate skills for writing effective image descriptions for critical visual content.
Microsoft have also written guidance for Everything you need to know to write effective alt text