Invisible disability

Invisible disabilities are disabilities that are not immediately apparent. For instance, some people with visual or auditory disabilities who do not wear glasses or hearing aids, or discreet hearing aids, may not be obviously disabled. Some people who have vision loss may wear contact lenses. A sitting disability is another category of invisible impairments; sitting problems are usually caused by chronic back pain. Those with joint problems or chronic pain may not use mobility aids on some days, or at all. Most people with RSI move in a 'normal' and inconspicuous way, and are even encouraged by the medical community to be as active as possible, including playing sports; yet those patients can have dramatic limitations in how much they can type, write or how long they can hold a phone or other objects in their hands. Non-blind people with the circadian rhythm disorder "non-24" are as a rule unemployable and there are no visible signs of that.