Many families and experts have dismissed them as "snake oil" while others swear by them.

Angela Dewney is in the latter group, and purchased two pairs of glasses with coloured lenses for her teenage boys.

Her oldest son Silas wears blue lenses, and her younger son Noah wears yellow lenses.

"I don't understand the science behind it, but they do work," she said.

Silas, who is in year 9 at Templestowe Secondary College, said he struggled to read before wearing the glasses.

"The letters would move around on the page, or merge into one. It was a big mess," he said.

"When I wear the glasses the letters and numbers stay in the same spot."

But Julie Mavlian, an administer of the popular Dyslexia Support Australia Facebook page, bought coloured glasses for her son and said they did nothing.

"We were waiting for it to make the miraculous difference, we never got there," she said.

"My son was happy to wear them, people told him he looked like Bono. People were looking at him like he was a rock star and not someone who couldn't read and write."

Silas Dewney with his brother Noah, 12. Photo: Penny Stephens

She said parents of children with dyslexia were vulnerable to so-called "treatments" which were not backed by evidence.

The controversy over the glasses has spilled into a conference being held at the University of Melbourne on Saturday and in Sydney next month.

Many dyslexia groups and experts are refusing to support the Learning Difference Convention because they say it promotes therapies that are not backed by scientific research.

They have raised concerns about keynote speaker, University of Oxford professor John Stein, who will be discussing the benefits of yellow and blue lenses and filters for dyslexics, as well as "music, rhythm and mindful movement training and omega three fatty acids".

Royal Australian and New Zealand College of Ophthalmologists spokesman Professor Frank Martin said there was no scientific evidence supporting "fringe therapies" like tinted lenses.

"It's a big expense with no clear benefit," he said.

"When a child wears them it draws attention to the child, they get more attention from the teacher and probably shows some improvements but there is no scientific evidence that the tinted lenses do any good at all."

But Professor Stein said research showed that yellow and blue lenses helped fix vision problems and improved children's ability to read.

He said coloured lenses were not a magic bullet, but helped people with a particular set of vision symptoms including blur and letters splitting into two.

"The controversy arise for several reasons," he said. "Most people in the field believe that vision has no part to play in reading, they are saying that the problem with dyslexia is entirely phonological."

Australian Dyslexia Association president Jodi Clements said dyslexia could not be 'treated' with coloured lenses or visual treatments.

"Dyslexia is language based and neurobiological in origin," she said.

"Dyslexia primarily affects acquiring and using language, particularly reading. Individuals with dyslexia require educational instruction that is direct, explicit, structured and language based."

Macquarie University's special education centre also warns against using tinted lenses, saying they "may divert resources from evidence-based reading interventions".

Jillian Zocher, a learning difficulties consultant who runs the convention, said "reading purists" had set out to undermine the event.

"They only focus on reading," she said. "We also have to address co-existing difficulties. These glasses try to address visual processing and help with light sensitivity."