Restoring Partial Sight: Bionic Eyes and How They Work

By Talia Beechick

It has been tested, and the rumors are true. Bionic Vision Australia’s recently developed bionic eye restored a severely blind patient’s vision for a brief moment.

The patient, Dianne Ashworth, suffers from retinitis pigmentosa or RP, which is a genetic condition. RP causes the cells—the rods and cones—on the eye’s retinal wall to die, prohibiting the eye from capturing images from the visual field, according to the Foundation Fighting Blindness. RP is typically diagnosed in teens and young adults, and most victims are completely blind by age 40. Foundation Fighting Blindness estimates that 100,000 Americans suffer from RP that is caused by gene mutations inherited from one or both parents. These mutations disrupt the proper creation of protein for the eye.

What is Bionic Vision Australia?

This is where Bionic Vision Australia (BVA) steps in. BVA brings together a wide range of experts through a national consortium of researchers from the Bionics Institute, Centre for Eye Research Australia, National Information and Communications Technology Australia or NICTA, and the Universities of Melbourne and New South Wales. In their research, ophthalmologists, biomedical engineers, electrical engineers, psychophysicists and surgeons closely examine the human eye and the concept of blindness, according to Science Daily. Their main, overarching goal is to restore vision to those suffering from blindness, an extensive project funded by a $42 million grant from the Australian Research Council in 2009.

Nvate Bionic eye by bionic vision Australia high-acuity device and wide-view device argus II

How the wide-view device works

BVA is divided into two principle programs with the first being the “wide-view program.” According to BVA, this program is designing a prototype that specifically targets the ability to distinguish between light and dark, and to visualize large objects, according to the BVA website. This will help people distinguish between depths and to know when to walk around objects and to distinguish stairs. This prototype is a retinal implant with approximately a hundred electrodes. This will aid those with severe vision loss in regaining both independence and mobility.

Nvate Bionic eye by bionic vision Australia high-acuity device and wide-view device argus II

How the high-acuity device works

The second program, the “high-acuity program,” hones in on a more detailed sense of sight. Experts have developed a retinal implant with 1,024 electrodes for patients to recognize faces and read large print.

How Do the Prototypes Restore Partial Vision?

BVA describes their end creation as a camera attached to a pair of glasses worn by the patient, but the early prototype being tested on Ashworth does not have an external camera. The camera is able to capture the visual scene and send radio frequency signals to a microchip implanted in the eye. With the prototype currently being tested, 24 electrodes attached to the microchip then convert the received signals into electrical impulses, stimulating the remaining cells in the retina connected to the optic nerve. The visual processes in the brain then decode these as images and, voila, vision.

However, BVA states that the vision restored to patients will not grant them healthy vision. Because the retinal implant aims to stimulate several spots of light across the visual field to create an image a patient may put together and understand, the implant will take both time and training to get used to. The more electrodes in the implant, the more light spots can be generated, allowing for greater detail in the patient’s vision.

The device that a patient is fitted with depends on a healthy optic nerve and the patient’s developed visual cortex. In other words, the patient must have been able to see previously before becoming blind due to RP or age-related macular degeneration. Those with total blindness will be the first to benefit from the bionic eye. Researchers are hoping to eventually develop a prototype to help those with low vision as well.

According to BVA, they are currently in the process of testing the prototype to ensure its safety and efficiency. This involves trying various levels of electrical stimulation with Ashworth and recording what she sees each time the implant is switched on.

When Will Bionic Eye Hit the Market?

Commercial development and availability will begin once the bionic eye clears these tests with successful results. “We are still in the research phase of our development and it will be some years before a commercial device is available on the market,” Veronika Gouskova, director of marketing for BVA, said. “We have commenced a patient study with three people who have received an early prototype bionic eye. Outcomes from this important study will inform the ongoing development work for our wide-view and high-acuity devices. Further patient tests with these full devices will commence in the next 12 to 18 months.”

Similar bionic eye projects are underway in other countries, including Germany and the United States. BVA explains that although all projects share the underlying theme of stimulating cells in the retina to result in restored vision, technical differences arise in how to achieve this goal.

Another Bionic Eye: The Argus II

One such product is the Argus II, which was originally developed in California by Second Sight Medical Products. Like the BVA prototypes, the Argus II utilizes a video camera that is attached to a pair of glasses. The Argus II differs in that “the video is sent to a small patient-worn computer where it is processed and transformed into instructions that are sent back to the glasses via a cable,” according to the product’s website. These instructions are then transmitted wirelessly to the implant.

Nvate Bionic eye by bionic vision Australia high-acuity device and wide-view device argus II

The Argus II by Second Sight

The Argus II continues to be tested in the United States and Europe. For more information on the clinical trial, visit the clinic trial’s website. Although the study is ongoing, participants are not being recruited, according to the website.

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