Sue, 47, who lives in Farringdon, called into Sunderland Specsavers one Saturday morning last October, little realising what the outcome would be.

Optometrist Ruth Moore, 24, spotted something wrong with Sue's left eye: a small lesion at the back that shouldn't have been there, and got in touch with Sue's doctor immediately.

Though Sue was in good health, her examination showed that all was not as well as she had thought.

She was diagnosed with a rare form of cancer which affects about 500 people in the country and was referred to Liverpool for treatment, after further tests at the Sunderland Eye Infirmary with Doctor Chris Wood.

Sue said: "I took it all in my stride until Dr Wood told me it was a cancerous tumour.

"I thought I was going to lose my sight, and that the cancer would move into my brain.

"They called my brother, Mark, to come down because I was in shock.

"The only room they could take me to was the chaplain's room and I just sat there and thought 'is this a sign?'"

After more tests, Sue was told that the cancer, if it spread, would go through her blood and into her liver.

Sue said: "I'm not out of the woods yet, but I want to raise awareness of the importance of having regular eye examinations.

'If I didn't get my eyes tested, who knows how long it would have been before I realised something was wrong?

"If left, it would have spread to my liver, which is fatal."

Sue, who works for Sunderland City Council, was referred to the Royal Liverpool and Broadgreen Hospital in Liverpool at the end of last year.

In January, she was treated using proton beam radiation therapy, and is now awaiting the results of a biopsy.

Sue said: "I had the biopsy under local anaesthetic, which was pretty awful.

"In fact, it was the worse thing ever.

"I could see the tubes as they entered my eye and when they cauterised the area the smell was horrific.

"Listening to the other patients was like hearing science fiction. I had no idea of the things they could do with your eye."

Sue has been told she stands a 95 per cent chance of being given the all-clear, and a maximum 25 per cent chance that she may lose some of her sight.

Sue said: "We are very lucky to have the Sunderland Eye Infirmary on our doorstep.

"Not everyone has access to somewhere as good. Some of the other patients in Liverpool were in bits but I had been well prepared by the Sunderland specialist, Dr Chris Wood, and I knew what to expect.

"It hasn't been a pleasant experience but with the support of my family and friends I got through it – and I know that so many people have had it much worse than me.

"I am so, so thankful I came in for a test that day."

>>Read more in Monday's Sunderland Echo