Perth twins Caitlin and Bethany Hannen-Williams have faced many challenges since they began losing their sight four years ago but one battle their mother did not predict was a fight for them to be taught braille.

The girls are going blind due to a degenerative condition called optic neuropathy and Raquelle Hannen-Williams believes learning braille could give her daughters the best chance to achieve their goals in life.

She lobbied the WA Education Department intensely for braille lessons for the girls, but they were offered short-term lessons of only one hour a week.

The department's assessment of Caitlin, who is now 12 and legally blind, states "to introduce braille at this time would create an unnecessary burden for her and would prevent her from achieving her potential in the classroom".

"So I think to myself, how many other children in WA are in the same position?" Ms Hannen-Williams said.

"Their parents don't even know that their children should be learning braille and how much of an advantage that child would have and how much better their outcomes would be if they were given braille."

Caitlin Hannen-Williams has been learning braille at home. ( ABC News: Rebecca Turner )

In frustration, Ms Hannen-Williams began teaching Caitlin braille herself - despite not knowing the script - and later secured some funding from the National Disability Insurance Scheme.

This has enabled Caitlin to study braille before school via FaceTime with a teacher in New South Wales, but this funding runs out in August.

Braille 'key to future success'

For many blind and vision-impaired people, braille is an important tool for leading an independent life, from going into the correct toilet or selecting a floor in an elevator.

Australia's former disability discrimination commissioner Graeme Innes was born blind and began to learn braille at the age of three.

He said braille was a critical literacy skill which taught spelling and punctuation.

Mr Innes said he had come across many highly intelligent vision-impaired people whose careers had been held back by poor spelling because they had learned via audio, not braille.

"For anyone who is blind or losing their vision, the earlier they can learn it and the more thoroughly they can learn it, the more successful they'll be in their career," he said.

He supported Ms Hannen-Williams' efforts in preparing her daughters for a future where they would need to use braille to study and work.

"I don't want her to think that just because she's going blind, she's only able to do menial tasks," she said.

"I don't want her [Caitlin] sitting at home on a disability pension. I expect that just because she's lost her sight she's still the same person she would have been if she still had her sight."

Caitlin Hannen-Williams loves books but finds sight reading exhausting. ( ABC News: Rebecca Turner )

Always at the back of her mind is the reality that Bethany - who has lost only 25 per cent of her vision - will also need to start learning braille.

Ms Hannen-Williams said Bethany was "in denial" about her failing eyesight, although she had witnessed her sister struggle to adjust, having to give up competitive swimming and accepting she will not be able to drive a car.

But today Caitlin is highly motivated to learn braille, loves reading Harry Potter books and wants to be a film actress when she grows up.

"It's up and down. It's a rollercoaster," Ms Hannen-Williams said.

"When she was between 11 and 12 she went through a rough patch, a grieving period. And she did get very angry, very emotional."

But there could be a glimmer of hope. After being contacted by the ABC, the WA Education Department said it expected Caitlin's braille services would be increased when she was reassessed next month.

"I think from what you've described, there's no doubt that this child needs more access to braille and I'm sure that's what will be organised," executive director of statewide services Lindsay Hale said.

The department said there were 17 students learning braille in WA, with 25 teachers qualified to teach the script. Students can have up to 4.5 hours of tuition a week.