When Tessa Protheroe’s children were diagnosed with autistic conditions she naturally vowed to do the best for them.

But by an incredible chance the help she sought for her sons led to the diagnosis of an eye condition she had been unknowingly living with all her life.

Mrs Protheroe, from Barming, was born with a condition called Prosagnosia, or facial blindness.

It meant that she could never see someone’s whole face, only parts of it. She also had a spatial awareness problem which meant she found it difficult to get from A to Z, even on simple journeys.

Mrs Protheroe, 39, said: “Over the years I think I adapted.

“I would recognise people through hairstyles, or some other feature. I just thought I was bad with faces and would have to try harder.

“I also couldn’t remember simple journeys like finding my way to a restaurant toilet and back and would have to go in a group.”

Mrs Protheroe’s nine-year-old son Tim has Aspergers Syndrome and Glyn, eight, was diagnosed with autism and dyslexia.

As she researched the conditions she found out about Ian Jordan, who has pioneered research discovering a link between autistic conditions and visual problems.

In 2006 she took her family to see the Scottish-based expert for an assessment, after Glyn said words often jumped around the page when he tried to read.

When Mr Jordan said sensory problems were common in children with dyslexia it clicked that his description sounded similar to her own experiences.

Mrs Protheroe was tested with different coloured lenses and when she wore a green tint she could see whole faces perfectly.

Two weeks later her sensory problems were resolved.

Through wearing the coloured lenses, Glyn’s ability to read has improved and Tim can read facial expressions better.

With facial blindness retinal cone cells do not work properly and cannot process certain colours, leading to the distorted or missing faces.

The coloured lenses mimic a healthy retina, allowing someone to see instantly.

Long-term use of the glasses can re-train the retina and the brain, in some cases, to see properly in any light.

Mrs Protheroe said: “I now no longer wear the glasses as they have trained my brain to catch up and develop the senses I was missing.

“Life is so much different now. A person’s smile means so much more now I can see a whole face.”

Mrs Protheroe believes more could be done to promote the link between autistic spectrum conditions and visual problems.

Only a few opticians in the UK offer the different coloured lenses which have made such a difference to her life and those of her sons.

Ian Jordan, director of Orthoscopics, who pioneered the research, said: “I would like all opticians to have this equipment, but only around 12 in the UK do.”

Mrs Protheroe added: “ Visual problems in autistic children can often go unnoticed. I would like parents to be aware there can be a prevalence of visual problems in children on the autistic spectrum and encourage them to explore every angle.”