A mystery virus is causing one of the country's most unique animals to go blind.

Key points: Lumholtz's tree kangaroos normally live in the rainforest canopy

Lumholtz's tree kangaroos normally live in the rainforest canopy In recent years they have been found disoriented in schools and on roads

In recent years they have been found disoriented in schools and on roads One theory is the leaves they eat are increasing in toxicity due to weather changes

Lumholtz's tree kangaroos are only found in a small pocket of rainforest in far north Queensland — and most Australians do not even know they exist.

Now, the creatures — which normally nestle high up in the treetops — are being found in odd places on the Atherton Tablelands, west of Cairns, including in schools, sheds and in the middle of roads, unable to see and confused.

A researcher has said the loss of the kangaroos' vision was likely caused by a virus potentially caused by changing climatic conditions.

Dr Andrew Peters has been investigating the animals' tissue. ( Supplied: Shane Raidal/Charles Sturt University )

Veterinarian Andrew Peters, a senior lecturer in wildlife health and pathology at Charles Sturt University, has been examining tissue from the affected animals and has found evidence of optic nerve and brain damage.

"We have some evidence to suggest that this may be a new viral infection, potentially even a new virus," Dr Peters said.

"What we know is a lot of wildlife diseases, particularly new viral infections, are caused by changes to the environment."

Normally near-impossible to find

Karen Coombes has been caring for injured tree kangaroos on her property near Malanda, west of Cairns, for two decades.

She studied the species for her PhD and founded the Tree Roo Rescue and Conservation Centre.

Most of the animals in her care are blind.

The little-known marsupials are among Australia's most unique native animals. ( Supplied: Dr Karen Coombes )

"Seven years ago, my husband and I would rescue a couple a year — mostly [after] dog attacks and car strikes," Dr Coombes said.

"And then there was this one 'roo in particular that I noticed was bumping into things.

"And that's when the penny dropped."

She said the tree kangaroos, which are normally near-impossible to spot in the treetops where they live, are being found in strange locations.

"Because they can't see properly, they are getting confused and ending up in places where they shouldn't be, like schools and backyard sheds," Dr Coombes said.

Toxins possibly causing blindness

She said she believed successive dry periods in the area had contributed to the species' eye problems.

Dr Coombes says blind tree kangaroos have been found in unusual places due to their vision loss. ( Supplied: Tree Roo Rescue and Conservation Centre )

The marsupials exclusively eat the leaves of the rainforest trees they inhabit.

"The leaves are fairly toxic but because we have had drier-than-normal weather over the past seven years, the leaves are probably more toxic than normal," Dr Coombes said.

"Because the trees are getting less water, those toxins might be concentrated more."

Dr Andrews said the theory was plausible.

"It's definitely a suggestion worth looking at," he said.

"The most important thing is that we detect this early, work out what's caused it and what's behind that.

"Then we can work with communities to start to build solutions and to help change the way kangaroos are behaving."