Spoiler alert: everything looks ghostly, out of place

Aug 4, 2015 08:49 GMT  ·  By

In the US alone, reports speak of about 20 million people aged 18 or older who struggle with vision loss. What's more, health officials expect that, by 2030, this figure will double. 

Scientists are well aware of the problem, and so efforts are underway to develop sight recovery therapies that might help those left blind by one condition or another regain their sense of sight.

However, there is one teeny tiny problem that is yet to be taken care of, researchers at the University of Washington argue in a new study in the journal Philosophical Transactions B.

Not to prolong the suspense, here's what this problem is: as promising as some sight recovery therapies might seem, the fact of the matter is that there is no telling how patients will respond to them.

Plainly put, it is still unclear how folks who opt for one sight recovery therapy or another will see the world once they undergo all the right procedures supposedly meant to restore their sight.

“Little is known about what the world will look like to patients who undergo those procedures,” the Washington University team says.

Sorting out the mystery

Looking to determine what the world would probably look like to somebody who has undergone sight recovery therapy, the Washington University researchers carried out a series of simulations.

First, they tested how an electric visual prosthesis, i.e. a bionic eye, designed to enable vision by stimulating nerve cells in the eye via electrodes placed on the retina, would alter the appearance of the world.

The scientists found that, rather that produce clear images, such a prosthesis would produce distorted images. This is because nerve cells in the retina would all receive the same stimulation, not at all how actual sight works.

“The retina contains a vast diversity of cells that carry distinct visual information and respond differently to visual input,” explains study co-author Geoffrey Boynton.

“Electrically stimulating the retina excites all of these cells at the same time, which is very different from how these cells respond to real visual input,” the specialist goes on to detail.

Then, the team turned their attention to how a therapy known as optogenetics would affect the sense of sight. This therapy aims to restore sight by inserting proteins into retinal cells in order to make them light-sensitive.

The scientists found that, like the bionic eye, optogenetics would fail to properly restore vision. Instead, it would produce sluggish and quite blurry images.

In the video below, the first panel shows the desired effect of either of the two sight recovery therapies that were put to the test. The one in the middle shows the images a visual prosthesis would produce, and the last documents the effect of optogenetics.

Patients need to know what they're up for 

Emerging sight recovery therapies might look good on paper, but as demonstrated by their study, they aren't all they're cut out to be, the University of Washington researchers argue in their report in the journal Philosophical Transactions B.

No, this does not mean that scientists should stop experimenting with bionic eyes and other treatment options altogether. It just means that patients need to know what they're getting themselves into when volunteering to receive one of these experimental therapies or another.

“This is a really difficult decision to make. These devices involve long surgeries, and they don’t restore anything close to normal vision. The more information patients have, the better,” says study lead author Ione Fine.

The black and white images show visual distortions that might result from electric prostheses
The black and white images show visual distortions that might result from electric prostheses

Photo Gallery (2 Images)

Researchers put sight recovery therapies to the test
The black and white images show visual distortions that might result from electric prostheses
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