Rather than just being for seeing, service dogs for people with autism and other disabilities can be used for several other things. These include:
Protection: For many people with autism, who often cannot tell untrustworthy people, dogs can sense danger. A service dog could growl at a man who pulls up in the streets asking someone with autism to get in their car. This growling could also alert police if they are nearby. For autistic people who have parents or caretakers who try to harm them, a dog could attack in defense of their owner.
Company: Service dogs can provide a person with autism company when they feel alone. A dogs loving, nonjudgmental company can give autistic people a feeling of self-worth and the ability to feel loved.
Alarm System: Over a year ago, an autistic man died in a van after being left alone in there for hours. Four years ago, an autistic child became traumatized by being left on a bus because he wasn't able to communicate where his home was to the driver. This left his scarred but with a service dog, who could bark if the driver missed their house, this could be prevented. An autistic man dying from being left in a car because of neglectful parents or caretakers may not happen because the dog's bark could alert people walking by the car that someone is locked in there.
Second Opinion: Dogs have the ability to tell if humans are telling the truth or not. Dr. Andrew Wakefield produced counterfeit evidence last year suggesting that vaccines are the cause of autism. Several autism "charities" also pay more money to their executives then they do to services for people with autism. This unfortunately drains communities of their ability to provide services for people with autism. If a service dog was around a person such as Dr. Wakefield or an organizer of a charity that didn't give it's money's worth, they could bark or growl to alert people to their dishonesty.