Adapted cycles make cycling accessible to all, whatever your personal challenges. There are a wide range of disability cycles that suit people with a variety of learning and physical disabilities, as well as health issues. Here is a brief overview of what bikes are available.
This is an introduction to adapted bikes, but it is also important to remember that it's possible to modify a standard 2-wheel bike to suit your needs (e.g. by wiring brakes and gears onto one handle, adding a foot plate to a pedal or increasing handle bar height).
The cycling world abounds in ways and means of reconfiguring wheels, pedals and seats so that almost anyone can ride. Special cycles can be tailored to an individual's needs, but most problems have readymade solutions.