Big Brother star Reggie Sorensen speaks about living with an invisible illness now she's legally blind.

Big Brother season three winner ‘Reggie’ Bird — known now as Regina Sorensen — has just 10 per cent of her central vision left.

Just one year after she became the first Australian woman to win the reality show, Sorensen was diagnosed with a degenerative eye condition known as retinitis pigmentosa. Specialists told the then-29-year-old she would eventually lose her vision.

That was 2004; more than a decade later, the single mum of two is now legally blind.

“I’ve lost my peripheral vision and I’ve got 10 degrees of central vision left. I have no night vision,” she explained during a segment on The Daily Edition yesterday.

Miss Mia is nearly as tall as me!

A photo posted by Regina Sorensen (@reggiesorensen) on Jun 20, 2015 at 10:44pm PDT

Sorensen also highlighted the difficulty and frustration of living with an ‘invisible’ health condition, telling hosts Sally Obermeder and Tom Williams, “unless I have my cane with me, people [don’t] realise I have low vision.”

“Sometimes when I forget to take my cane to the shops and I bang into people … they look at me because I’m so young and just think I’m being rude,” she explained.

“Even when you’re getting a taxi — I’ve had a few say, ‘You’re only going up the road, why can’t you walk?’ Things like that upset me’.”

To help prevent these misunderstandings from happening, Sorensen tries to wear her ‘I have low vision badge’ every day.

When she forgets to do so, it’s a major source of anxiety. “I know I’m going to bang into people and then I’ve got to explain, ‘Sorry I didn’t mean to, I can’t see’ and then they just look at me as if to say, ‘What a load of rubbish’,” she said.

Sorensen says her kids are a great source of help and support. Her daughter Mia came to her aid during a recent visit to the movies when she tripped over a girl in the aisle.

“That was a bit embarrassing, I didn’t see her at all. I felt awful, I kicked her — she nearly went flying down the stairs,” Sorensen recalled.

“Mia had to come back and grab my hand and help me to get out of the theatre.”

Reggie at the Melbourne Cup in 2005. (Image: Getty)

During her appearance on the Channel 7 show, Sorensen also explained why she wants her son Lucas, who has cystic fibrosis, to have a normal childhood despite his illness.

"[With kids with cystic fibrosis] you've got to be aware of germs, and you're forever using hand sanistiser and wipes and they're not meant to play in dirt," she said.

"But I feel like if I kept him inside all the time, we wouldn't have a very happy life."

*Featured image: Instagram/Regina Sorensen.