system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Do animals that are trained to help people with disabilities or medical issues really understand their owners are blind, deaf, etc.?

I just wanted to know if medical assist dogs or dogs that help people with disabilities know if a person is blind or they just respond to certain behaviors of the owner? How are they trained, for example, to know to stop a blind person from crossing the street? Do they understand the person can't see?
gpt
It's all training. They're trained by sighted people, and they'll do what they're trained to do whether or not the person they're guiding is blind.  They know to stop before crossing the street because they've gone through a long training process that taught them that's what they're supposed to do when they come to a street.