A mother-of-three was inspired to run the London Marathon to raise money for charity after being diagnosed with a rare form of cancer.

Ruth Johnston, 44, of Hampton, was diagnosed with ocular melanoma - a rare form of eye cancer - in 2015.

The married mum, who is now partially blind in one eye, is training for the London Marathon to fundraise for OcuMel UK, a charity who focus on eye cancer support and who helped her through the ordeal.

Mrs Johnston said: “For a long time I was really terribly scared and I didn’t know how to cope.

“One of the reasons I decided to run the marathon is to keep my mind on other things and to stop me thinking about cancer as much as possible.”

Mrs Johnston had no symptoms and only got referred to Moorfields Eye Hospital after her opticians spotted worrying signs.

She was diagnosed with a small tumour and had to receive plaque radiotherapy.

The treatment involved having a small radioactive disc stitched to her eye which reduces the tumour over a period of time.

Last year, Mrs Johnston was told the tumour is now inactive, but it could become active again at any time and she will have check-ups for the rest of her life.

She is now partially blind in her left eye and will eventually lose all vision in that eye.

Jo Gumbs, director of OcuMel UK, said: “We applaud Ruth in her efforts in running the London Marathon to support us.

“Our members know what it’s like to have a rare cancer and the difficulties this brings them.

“As Ruth’s case illustrates going for regular eye tests is so important. We work with many people who have had their cancer diagnosed as a result of having an eye examination and in some cases this has saved or prolonged their lives.”