625 ILCS 5/1-159.1

A natural person who, as determined by a licensed physician, by a licensed physician assistant, by a licensed advanced practice registered nurse, or by a licensed physical therapist: (1) cannot walk without the use of, or assistance from, a brace, cane, crutch, another person, prosthetic device, wheelchair, or other assistive device; (2) is restricted by lung disease to such an extent that his or her forced (respiratory) expiratory volume for one second, when measured by spirometry, is less than one liter, or the arterial oxygen tension is less than 60 mm/hg on room air at rest; (3) uses portable oxygen; (4) has a cardiac condition to the extent that the person's functional limitations are classified in severity as Class III or Class IV, according to standards set by the American Heart Association; (5) is severely limited in the person's ability to walk due to an arthritic, neurological, oncological, or orthopedic condition; (6) cannot walk 200 feet without stopping to rest because of one of the above 5 conditions; or (7) is missing a hand or arm or has permanently lost the use of a hand or arm.