Images should be used purposefully in online courses. This tutorial provides some guidelines how to use images in Moodle (WebAccess), but the principles apply to any LMS or online distribution tool.
Accessibility Tutorial – Images from M. Ricardo Flores on Vimeo.
Hyperlinks can be quite troublesome for people who require screen readers if the hyperlinks have not been appropriately created. This video explains how to address this.
Accessibility Tutorial — Hyperlinks (captioned) from M. Ricardo Flores on Vimeo.
Staying with the accessibility theme. Here is another video that explains how to use contrast for accessibility.
Accessibility Tutorial — Contrast from M. Ricardo Flores on Vimeo.