Monday, March 28, 2016

Welsh woman receives "bionic eye"

A photo of a human eye looking into the camera.  The iris is mostly blue, with some light brown surrounding the pupil.  There appears to be some light mascara on the eyelashes.
 Photo courtesy Laitr Keiows/Wikimedia Commons

A woman from Wales recently regained some of her sight after a rare disorder caused near-complete loss of vision.  Now she is learning to see again—and it’s all thanks to a real-life bionic eye.

Rhian Lewis was given the implant last June, in an operation that took place at John Radcliffe Hospital in Oxford, UK.  The implant takes the form of a tiny, 3x3mm chip that contains about 1,500 light sensors that send electrical signals to her nerve cells (see a picture of it here).  The chip is powered by a metal coil connected to a small computer that is placed underneath the skin behind the ear, and from the outside, the whole thing looks similar to a hearing aid.

The resolution isn’t very good yet—it’s less than 1% of a single megapixel—but it’s enough to make a big difference for Lewis, who has been virtually blind in her right eye for 16 years.  The 49-year-old from Cardiff, Wales recently went in for follow-up testing of the device at John Radcliffe Hospital, where she received the implant as part of an ongoing trial.  One of the tests involved looking at a cardboard clock the researchers had set up to see if she could see where the hands were pointing.  When Lewis correctly identified the time depicted, she said it felt like Christmas day.

Lewis has retinitis pigmentosa, a condition that destroys light sensitive cells in the retina.  She’s never had vision in dim lighting at all, and about 16 years ago she lost all vision in her right eye and most vision in her left.  She says it’s been about eight years since she’s know what her children look like.  And the condition affects simple things too, she continues, like going clothes shopping and not being able to tell what she looks like.  Now she says she gets excited every time she’s able to do something like find a spoon or fork sitting on the table.

It wasn’t an instant change.  It takes a few weeks for the human brain to learn how to interpret the signals from the type of implant she received, and at first the only things perceived by the patient are bright flashes.  Lewis is able to adjust the device’s contrast and sensitivity using dials on a hand-held power supply, though, and she is continuing to practice interpreting the signals it sends to her.  The images may not be very clear yet, but for Lewis, the experience of seeing them at all is exhilarating.

The team behind the implant hopes the technology can one day be used by people with other types of visual impairment, such as age-related macular degeneration.

You can learn more about Rhian Lewis and her "bionic eye" from The Guardian, as well as from the BBC.

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