'New brain implant restores visual perception in blind'

Scientists claim to have developed a brain implant that can enhance users' ability to navigate the world by restoring their capacity to detect movement, and distinguish light and dark.

The device called Orion is geared to people who used to be able to see but lost their vision to injury or disease, according to researchers at the University of California, Los Angeles (UCLA) in the US.

"This is the first time we've had a completely implantable device that people can use in their own homes without having to be plugged into an external device," said Nader Pouratian, a neurosurgeon at UCLA Health and principal investigator of the five-year study.

"It helps them recognise, for example, where a doorway is, where the sidewalk begins or ends or where the crosswalk is. These are all extremely meaningful events that can help improve people's quality of life," Pouratian said.

While the implant doesn't provide normal sight, it enhances users' ability to navigate the world by restoring their capacity to detect movement and distinguish light and dark, the researchers said.

The system wirelessly converts images captured by a tiny video camera mounted on sunglasses into a series of electrical pulses, they said.

The pulses stimulate a set of 60 electrodes implanted on top of the brain's visual cortex, which perceives patterns of light and interprets them as visual clues, according to the researchers.

Along with the glasses, the system also includes a belt equipped with a button, which patients can press to amplify dark objects in the sun, and press again to visualise light objects in the dark, such as an oncoming car's headlights at night.

Six people have received the implant: the first three at UCLA Health, two at Baylor College of Medicine in the US and the sixth at UCLA.

"I'll see little white dots on a black background, like looking up at the stars at night," said Jason Esterhuizen, the world's second research subject to receive the device.

"As a person walks towards me, I might see three little dots. As they move closer to me, more and more dots light up," said Esterhuizen, 30, who moved from his native country South Africa to participate in the clinical trial at UCLA.

Recipients have expressed delight at once again being able to enjoy fireworks and blow out candles on a birthday cake.

The implant currently stimulates the left side of the patient's brain. As a result, they perceive visual cues only from their right-side field of vision.

Ultimately, the goal is to implant both sides of the brain to recover a full field of vision, researchers said.

"This device has the potential to restore useful vision to patients blinded by glaucoma, diabetic retinopathy, cancer and trauma," Pouratian said.

With research subjects' input, he and his colleagues hope to one day adapt the device to also assist people who were born blind or have low vision.