Becky Crossthwaite, 13, started complaining of headaches, but was told by a doctor that it was just migraines and sent her away with paracetemol.
But when the headaches continued, Becky’s mum Kirsty thought she needed stronger glasses and took her to the optometrist - even though it had just been four months since her last examination.
And when optometrist examined Becky’s eyes she was surprised by what she saw.
Kiran Lally said: “I had only examined Becky four months earlier and her eyes were fine. But this time there was a lot of swelling of the optic nerve at the back of Becky’s eye called papilledema. I had examined Becky’s eyes just a few months earlier and there was nothing.
“It is caused by a build up of fluid around the brain and is extremely rare. An optician will probably only see one patient in their entire career with the condition.”
She knew that the likely cause of the papilledema was a brain tumour although she was unable to tell Kirsty and Becky of her suspicions as it needed to be confirmed by doctors after scans in hospital.
“My main thought was not to panic or distress Becky and Kirsty but I knew it was imperative that they get Becky to hospital straight away as it is normally caused by a something in the brain.”
Now, Kirsty and optometrist Kiran Lally are urging more parents to get their children’s eyes regularly checked.
Kirsty said: “I can’t believe that it isn’t the law that children have to have their eyes tested.
“It isn’t just about whether they can see, it can pick up things that can save their life, like it did with Becky.”
Ms Lally says it isn’t just life-threatening illnesses that can be detected.
“If a child has something like a lazy eye and we diagnose it early enough we can do something about it.
“But I get them coming in ant 15 and 16 and they have never had an eye test and by then it is too late.
“But I also get children coming in at ten and they can’t even see the white board. That is bound to have an affect on their learning.”
The Eye Care Trust charity estimates that one in five children has an undetected problem with their vision.
According to national screening guidelines, all school children aged four and five should be offered a vision test.
However, a report by the College of Optometrists found that less than a third of local authorities are providing them.
One in five children could be suffering from an undetected problem with their vision, according to the charity The Eye Care Trust.
All children should be offered screening at school aged four and five.
Eye tests are free to all children under the age of 16.
Children don’t have to be able to read to have an eye test.
If problems such as a lazy eye are detected before a child is seven, then they can normally be corrected with the right treatment.
For more information visit http://lookafteryoureyes.org/eye-care/children