Bar exam applicants who have disabilities can request special accommodations during the exam. Depending on the nature of the disability, "accommodations may include such things as assistants (i.e., readers or personal healthcare assistants), wheelchair access, permission to dictate to a typist or tape recorder, customized timing, separate testing room, customized examination materials (i.e., Braille, large print, etc.), extended testing days and permission to bring and use specific items or medical aids.
It's not a perfect system. You could fake a disability for the extra time on the test. You may even get away with it.
But if you get caught, you'll lose your license.