"As our Prime Minister said, this is the worst year of our lives and here I am as Australian of the Year during it," Dr Muecke said.

The choice of an eye surgeon as Australian of the Year in 2020 seemed particularly apt as Dr Muecke accepted the award from Prime Minister Scott Morrison in Canberra in January.

But few could have foreseen what's unfolded since Australia Day. By the time the global coronavirus emergency reached Australia, Dr Muecke had been booked for dozens of speaking engagements around the country.

Those opportunities to explain his life-changing work and eye health charity Sight For All were cancelled, one by one, as the COVID-19 crisis escalated.

"A lot of people have said to me 'Can't we extend it until next year?' and, no, we have to celebrate the heroes of the bushfires and the heroes from the pandemic," Dr Muecke said.

"The Australia Day awards need to continue and I just need to make as much of this year as I can."

And he certainly has done that, hosting live webinars, joining the National COVID-19 Health and Research Advisory Committee and even turning his kitchen and study into a film studio while social distancing at home with his family in South Australia so he could produce, with the help of son Nicholas, videos about the toxic dangers of sugar.

As an ophthalmologist, his focus for 2020 is on opening the eyes of Australians to type 2 diabetes, the leading cause of blindness in adults.

He hopes his videos and webinars explaining the toxic impact of sugar have taken his important message to a "broader audience" than he might have reached on a speaking tour.

National Australia Day Council chief executive officer Karlie Brand said, with nominations for 2021 Australian of the Year closing on July 31, it was time for Australians to nominate someone like Dr Muecke for their inspiring work.

"This year, perhaps more than any other since the awards began in 1960, we've seen Australians overcome many adversities, help each other in times of crisis and carry out acts of bravery, leadership and kindness on a daily basis," Ms Brand said.

"It only takes one nomination for someone to be considered for the awards, but a nomination must be submitted for a person in order for them to be in the running.

"No matter how well known someone may be, a public nomination must be submitted before they can be considered for the awards."

YouTube-famous maths magician Eddie Woo, who was the Australian of the Year Local Hero for 2018, already knows who he is nominating for 2021.

It's Sarah Gray, the founder of AusEE, which supports people caring for, or diagnosed with the condition known as eosinophilic gastrointestinal disorder.

"When my son was first diagnosed we knew so little about it. Even doctors we talked to were like 'what is that?'," Mr Woo said.

"The work of Sarah is incredibly valuable to us as a family."

He has since become AusEE's charity ambassador.

"I want to honour the work she has done and sort of thank her for the incredible contribution she has made to my family and I," he said.

"These are the sorts of people ... who help our communities function."

Mr Woo, a Sydney high school teacher whose "Wootube" maths tutorials - initially posted to help a sick student missing classes - made him a web hit, recently published a book, Woo's Wonderful World of Maths.

He and Dr Muecke feature on the new Everyday Heroes podcast series by 2020 Australian of the Year Local Hero Bernie Shakeshaft.