The 35-year-old is earning cash for Murray Opticians to thank them for the continued eye treatment he has received since he was a teenager.

Optometrist Alan raises funds for his wife Margaret’s Vision Aid Overseas expeditions to help the blind in third world countries. In the summer Margaret spent weeks helping blind children in Zambia.

Jay’s campaign called Jay 4 Nation Sensation has seen him complete half-marathons in Perth, Belfast and Warrington — and Cardiff is next on Friday.

He’s been sponsored by Naedanger energy drinks, Run4it sports shop and Murray opticians.

“It’s getting harder,” said the Drumchapel man. “But I’m still going at it — I’m determined to finish this and say thank you for all the help I have been given down the years.” At the age of 15 Jay found out he had an eye condition known as Retinitis Pigmentosa, or RP.

The teenager was prepped to join the Royal Air Force but had to cancel his dream after discovering the defect.

However, Jay found a new passion in martial arts and has won an incredible 49 trophies over the years.

But his eyesight was deteriorating and, by 2011, the former tae-kwon-do teacher had to give up his beloved sport and occupation.

In 2012 Jay’s two best friends lost their fathers to cancer and that is when the fundraising began in a kilt to give his runs a unique Scottish twist.

In that year alone the big-hearted athlete ran 28 races to raise funds for Cancer Research.

Jay’s Retinitis Pigmentosa has caused worsening tunnel vision and night blindness — which makes it difficult to see in low light situations.

“On five or ten kilometre runs my sister usually does them with me so I can hold onto her,” Jay said.

“But when it comes to the half-marathons I have to do them myself. When I ran in Belfast I fell after someone ran in front of me. It was only a mile in, so I got up and just got on with it.” He added: “Ideally, I’m looking for someone to do them with me.” Jay is extremely grateful for the treatment and care he has received from Alan and Margaret Murray at Murray’s Opticians in Drumchapel.

He said: “Murray’s opticians have done so much for me over the years — and it means a lot. I’ve been going there since I was 16 years old and since then they have given me free contact lenses, which has saved me a fortune.

“Mr Murray has helped me more than eye specialists. He’s done research for me and got all the information he could for me. He does a lot of charity work himself, so this is my way of saying thank you.” Alan Murray said: “James’s efforts are amazing — he works hard for it. He told me he was going to do these half-marathons and I’ve not seen him since.

“He’s really disabled with his eye condition and to be able to do that with almost no help - it’s a great, great achievement to do that and have the willpower to do it.

“Our trips with Vision Aid Overseas cost us a lot of money — but we’ve kept to it, it’s good to be associated with.” There is hope for curing Jay’s blindness as a new treatment is being tested at the University of Oxford, which he hopes to receive to save his vision.

You can donate to Jay’s 4 Nation Sensation via Murray’s opticians at Drumchapel Shopping Centre.