What is usability? If a door equipped with a push bar actually required me to pull on it in order to open it, I became upset. I considered it a bad experience due to poor usability.
Things we might normally think of as well designed are often only “well designed” within a certain context. People with limited use of their arms, for example, might find a standard door difficult to open, or a standard keyboard difficult to employ. Ditto those with impaired vision using browsers that might lack support for web standards, or relying on high contrast signage to find their way in the physical world. They often incur barriers when accessing the physical environment or the web.
Reference visit: The National Council for Persons with Physical Disabilities in SA