He may not be a black sheep but a wether named 64 — after the Beatles song When I'm Sixty-four — is a stand out in his paddock.

The ragged old sheep has been blind most of his life, and is now in the care of an animal refuge.

"Named him after the song, because when he came to us here, he was 12 in human years, so 64 for a sheep," Pam Ahern, co-founder of Edgar's Mission in Lancefield north of Melbourne, said.

Halo vest custom-made to fit woolly sheep

Bleating around in his paddock and lazily mulling over blades of grass, 64's defining feature is the wide plastic halo worn around his head.

With few options for vision-impaired animals and with no longer a herd to guide him, Ms Ahern began searching the internet for impairment aids for animals, eventually stumbling across the 'halo vest'.

The vest, invented in the United States, is designed to fit dogs, with a plastic halo preventing blind canines from walking into objects.

After getting in touch with the manufacturers, a vest was custom-made especially to fit 64's ruminant measurements.

Inventor of the HaloVest and president and CEO of Halos for Paws, Dorie Stratton, said she came up with the idea of the vest after rescuing a blind Scottish terrier.

"I found him abandoned in a Walmart parking lot, and I took him home to care for him," Ms Stratton said.

"Not being familiar with blind dogs, I went online to learn how to care for handicapped dogs.

"I found several sites that showed me how to make a blind dog collar."

Annabelle and her charge, blind sheep 64, are now inseparable. ( Facebook: Edgar's Mission )

After conceiving the idea, Ms Stratton and her friend Ellen Burgess, who had previously owned a blind dog that had since passed away, decided to make the idea a reality.

"We initially didn't have any plans to start a business, until we showed the vest to our vet ophthalmologist," Ms Stratton said.

"She went crazy for the vest and said these vests were highly in demand for blind dogs and I should start a business selling [them].

"I thought about it, and the rest is history."

Herd offers protection

Life for blind animals is tough and according to Ms Ahern, without his herd, 64 would not have had much chance of surviving to his old age.

"He had obviously been living as part of a herd that protected him, because he wouldn't have survived long alone being blind," Ms Ahern said.

"He wasn't socialised with humans; he was absolutely terrified of humans."

With few options for vision-impaired animals, the staff at Edgar's Mission took an inventive approach to guiding 64 around the 153-acre Victorian property.

They fitted a sheep named Annabelle with a bell — one that 64 was trained to listen for and follow.

However, according to Ms Ahern, the transition was harder than expected.

"It took a lot of training to get [Annabelle] wearing the bell and [to get] 64 following the sound," she said.

"Sheep are preyed-upon animals so naturally, they don't like making noise wherever they go."

After adjusting to the jingling collar, Annabelle and 64 are now an inseparable pair and play follow-the-leader around the property.

"Annabelle was actually named Annabelle before we paired her up with 64 [so] it worked out quite well," Ms Ahern laughed.