A routine eye test saved the life of a four-year-old Sussex girl when an optician discovered she had a brain tumour.

Shannon Williams was diagnosed with the life-threatening growth, which had grown to the size of a peach, after her optometrist spotted a slight colour-change in her eyes.

She had been suffering from headaches and had difficulty in walking but doctors put her condition down to viruses.

When she developed a squint her parents David and Becky, of Stoney Lane, Shoreham, took her for a sight test at their local branch of Specsavers.

The optometrist noticed her optic nerve was grey instead of pink and she was immediately taken for surgery.

Mr Williams, 40, said: "We had been concerned about her health for some time. She had a squint developing and had co-ordination problems. She was starting to walk peculiarly.

"She was also having terrible headaches and waking in the middle of the night screaming. Doctors had it down to viruses but when we got her eyes checked, the optician saw something he had never seen in any textbooks."

Shannon was rushed to Worthing Hospital where a consultant diagnosed hydrocephalus - a build-up of fluid putting pressure on her brain.

Shannon and her parents were taken to a specialist hospital in London where she was operated on the following day.

Mr Williams, a house-husband and father of five other children under 11, said: "The surgeon said had we waited any longer she would have gone into a coma and there was every chance she would not come out.

"When someone says something like that to you, your whole world comes crashing around you.

After a four-hour operation, in October Shannon was soon able to walk unaided and the Williamses are hoping for the all-clear later this month.

Shannon is her "bright, happy and naughty" self at Kingston Buci Infant School in Shoreham.

Mrs Williams, 29, a student hairdresser, said: "I had no idea your eyes can reveal so much about your general health. I urge anyone who does not have a regular eyesight test to do so."