One of the unique features of the Paralympic Games is the presence of guides in certain events.
Assistants are used by some Paralympians with vision impairments. For example, “guide runners” can be attached to an athlete by a strap on their arms or hands, but the athlete must finish ahead of the guide.
Some visually impaired cyclists also pair up with a guide who rides in front in a tandem and is known as a pilot. And for visually impaired swimmers there are “tappers” – assistants who tap the athlete’s head or body as they approach turns or the finish to keep them safe
Guides in track events for athletics:
In track events, athletes in class T11 (total visual impairment, etc.) and some athletes in class T12 (low vision) run with a guide runner who serves as a substitute for the runner’s eyes by providing visual orientation, staying together by holding onto a rope (tether) and running side by side. Sport Class T11 athletes run with the guide and Sport Class T12 competitors can choose whether to run with a guide runner or alone. Guide runners guide the athlete to the finish line while verbally communicating information about the course, times and surroundings, with athlete safety their top priority. Leading the runner or crossing the finish line ahead of the runner results in disqualification.— via Paralympic.org
Here are some snippets explaining the role of the guide at the Games:
(You can watch the full documentary ‘The Invisible Bond’ here.)