Darcey Fletcher was diagnosed with severe headaches and sent home by doctors at Barnsley Hospital but her concerned mum Chrissy took her to her local opticians, Auckland Opticians.
An eye test revealed Darcey had seven out of eight danger signs for brain tumours and she was rushed to Sheffield Children's Hospital where the family was told if the tumour hadn't been spotted it could have killed her within a week.
Just under an hour later, Darcey had an operation to remove the tumour – found to be benign and the size of a large orange.
Chrissy, 38, told her local paper: "Darcey had been ill for about a week in November last year and we thought it was a virus. I took her to the doctors because it was not going away and they said it could be migraines or a virus.
"They gave her tablets for migraines. We left it for about five days but she was still waking up screaming in pain.
"I got the doctor out on the Friday and he said to go to Barnsley Hospital."
Chrisssy, who lives with husband Ian, 46, and their four children in Huddersfield, West Yorkshire, had first taken her daughter to see a doctor on November 10 last year.
At the time little Darcey had been suffering from symptoms for a week.
She was prescribed migraine medication but after five days Darcey's symptoms continued and she was waking through the night screaming in pain.
On November 14, Chrissy took Darcey to Barnsley Hospital and explained her symptoms but was told there was no need for her to have a scan.
She said: "At the hospital Darcey was screaming her head off and she just wanted to go home. I got her Calpol and a sick bowl and I just wanted to get her home.
"After the doctor told me that she didn't need a scan I didn't push it. If a doctor tells you that she doesn't need a scan and to carry on with the meds, then that is what you do.
"As parents you listen to the doctor and when they say that, you believe them. But I knew she was in pain and it didn't make sense what the doctors were saying to me.
"I have no clue why Barnsley Hospital didn't scan her. They let a seriously ill little six-year-old girl out of their hospital and I listened to them.
"I can't believe they said she didn't need a scan, when Darcey was really distressed."
Chrissy said: "People need to be aware and trust their instincts as parents. If doctors tell you one thing but you can see your child in pain, then you should trust your instincts.
"I know my daughter. She was in a mess. I'm still a nervous wreck but we want to get her back to normal."
While her husband added: "I just can't thank the optician's enough. If it wasn't for the optician's Darcey wouldn't be here.
"They saved my little girl's life."
Barnsley Hospital haven't yet commented.
THE WARNING SIGNS THAT SAVED DARCEY'S LIFE
If your child has one of these, see your doctor. If they have two or more, ask for an 'urgent referral'.'
Brain tumour symptoms include:
• Persistent/recurrent headache
• Persistent/recurrent vomiting
• Balance/coordination/walking problems
• Abnormal eye movements
• Blurred or double vision
• Behaviour change
• Fits or seizures
• Abnormal head position such as wry neck, head tilt or stiff neck
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