A blind man claims he was turned away from a restaurant - because a worker didn't believe his service dog was legitimate.

Paul Castle made the allegations in a post on Instagram earlier this month.

He claims the incident happened at an unnamed restaurant in his home city of Seattle, Washington.

Paul says he walked in and a waiter quickly approached him, telling him no pets were allowed in the restaurant - including "emotional support dogs"."

Paul says he showed the waiter his dog's harness and offered to get his papers - proving it was a service dog - for proof.

But he was then allegedly told the restaurant would call the police if returned with his dog.

Paul then left but, in a follow up video, says he later went back to the restaurant, where he says he was told the waiter who denied him entry had recently had a negative experience with an "unruly" service dog."

The manager explained that this waiter had mistakenly thought this was a similar situation as Paul was able to sustain eye contact with him too.

Paul, who has lost more than 90% of his vision to the untreatable eye disease retinitis pigmentosa, is now calling for a better understanding of the blindness spectrum.

He said in the caption of his video: "Thank you everyone for having my back!"

"When this happened to me (and Mr Maple) I felt really sad and alone — but it's obvious we have an army of people behind us!!"

"The support means so much. I just hope this experience serves as an opportunity to learn."

"Not just for the server and the manager, but for anyone watching this who was unaware of the spectrum of disabilities and the distinction between trained service dogs and the growing problem with fake service animals."

"I personally believe there should be a nationally recognized ID card (like a driver's license) for people with certified service animals."

"It's hard to believe this doesn't exist yet! Perhaps this is a change we can all get behind?"

In a response on Instagram, Guide Dogs for the Blind said: "We're so sorry you had to go through that."

"Per the Americans with Disabilities Act, guide dogs (and all service animals) are allowed anywhere the general public is allowed, including restaurants."

"Handlers do not need to show paperwork, and business owners are only allowed to ask a few select questions regarding the nature of the service animal and the work they perform."