Linda, Special needs are typically handled by a specific office at your institution. Students that contact that office and register their needs can be provided the resources they need to be successful. Your institution office will typically provide instructors with information about any special needs and the appropriate accomodation that should be considered. Visual impairments, auditory impairments, etc. are a few that may arise. There has been a greater focus in the last few years on ensuring that online learning systems are accessible (can be accessed effectively with screen readers, etc.) as well. Herbert Brown III