Following a hypoxic brain injury, Sarah Hill has needed full-time care - but now, virtual reality is opening up new worlds, from deep sea to deep space, all from the comfort of her care home.

"I am unable to walk - and I can feel light and able to walk," she says. "You can go under the sea, look at all these fish. It reduces my anxiety. I find the virtual-reality kit very helpful."

After trials at multiple NHS trusts, the government says immersive technologies have the potential to "transform" therapy and healthcare.

And the interventions tested - using virtual-reality kits to treat pain and phobias, for example - could save the NHS £2m every year.

Ms Hill's physiotherapist, Pamela Hicken, says her VR kit "encourages movement" and interaction.

"I've had residents who can't talk who are now talking to people or animals in the video," she says.

VR has grown rapidly in the global healthcare sector.

Chief executive of the Welsh government's life-sciences hub Cari-Anne Quinn says: "Immersive technologies are helping to future-proof our health and social-care systems in Wales and beyond."

And Oxford VR founder Prof Daniel Freeman, who has supported the government's National Institute for Health Research, tells BBC News: "My view is it will play a major role in the future, due to the positive results we are seeing."

Also excited about the technology's potential is Rescape Innovation chief executive Matt Wordley.

"Framing it like a video game, we are in the arcade era," he says.

"What is coming down the line will be phenomenal.

"Challenges are ever-present though.

"The NHS has never had a VR budget, for instance."

But the Covid-19 pandemic has sped up the adoption of immersive technology.

"The pandemic has shown some things can be done quickly in the NHS, when you cut down some of the barriers," Mr Wordley says.

"We're having more positive conversations now."

Overall, the VR industry is expected to reach a value of $1.2bn (£900m) globally by 2024.

According to the communications regulator, Ofcom, one in 17 UK households had a VR headset at the start of 2020.

And the company Statista estimates 6.1 million will have been sold by the end of 2021.

But some experts warn of risks.

A report by VR businesses and government, The Growing Value of Extended Reality in the UK, identified potential problems, including nausea and fatigue, if the technology was poorly designed.