When designing courses it is important to consider accessibility, universal design, invisible disabilities, privacy, and more
” Accessible Design” calls for design that includes the needs of people whose physical, mental, or environmental conditions limit their performance. “Universal Design” aims to extend standard design principles to include people of all ages and abilities, but remains at the level of generality, so it does not address all the specific needs of any particular disability.
But even for people who do not have any specific physical or mental characteristics that affect computer use, it has been found that adopting universal design principles can reduce fatigue, increase speed, decrease errors, and decrease learning time for all users. In many ways, universal design addresses the larger issues of usability by making things easier for everyone. from Usability First (opens in a new window).
Invisible Disabilities is an umbrella term that captures a whole spectrum of hidden disabilities or challenges that are primarily neurological in nature.
from Disabled World: Invisible Disabilities Information/
To read more about what may constitute an invisible disability, please check the lists at the above site. Included as invisible disabilities are ADHD, autism, brain injuries, chronic pain, chronic fatigue, and many more conditions.