Australian rugby legend Michael Lynagh's sight has been severely damaged by a stroke but he admits that he is lucky to be alive.

The 48-year-old, a former Wallabies captain and World Cup winner regarded as one of the sport's all-time greats, was rushed to hospital with headaches and blurred vision two weeks ago.

He was released on Tuesday and on Wednesday addressed the media, speaking clearly, looking fit, and able to walk.

But he said he was finding it hard to cope with a 45 percent loss of sight in his left eye.

"My brain has been damaged in certain places," he told reporters.

"Forty-five percent of sight to the left has been lost, hopefully over time my eyesight will improve."

Lynagh, who is based in Britain, was in Brisbane on a visit when he fell ill during a meal and a couple of beers with friends. He said he laughed at a joke and choked, and when he stopped he could not see.

A split wall in an artery in the back, right-hand side of his neck caused the stroke which neurologist Rob Henderson said was rare in a fit person of his age, but often fatal.

"I understand how lucky I am. I'm just very, very fortunate," said Lynagh.

"As Rob said to me, 'you haven't just dodged a bullet; you've dodged a cannonball'."

AFP