What is the bionic eye?

The bionic eye is a retinal prosthesis designed to restore a sense of vision to people with profound vision loss due to degenerative retinal conditions. This technology makes use of a retinal implant surgically placed in the back of the eye, as well as an external digital camera and processor.

What is medical bionics?

The word ‘bionic’ is derived from a combination of the words ‘biology’ and ‘electronic.’ Medical bionics is the field of science at the interface of engineering, biology and medicine, which seeks to replace lost physiological functions through technical and electronic means.
There are three categories of medical bionic devices: those that send signals from the brain to another part of the body (e.g. bionic hand); those that send signals from the body to the brain (e.g. bionic ear); and those whose action is restricted to one part of the body without becoming part of the nervous system (e.g. cardiac pacemaker).
The most prominent Australian example of medical bionics is the highly successful cochlear implant, or ‘bionic ear’, developed at the University of Melbourne and the Bionics Institute, and commercialised by Cochlear Ltd.

What will bionic vision be like?

The bionic eye works by stimulating the perception of light in a patient. A phosphene is a perceived spot of light in the visual field. What our technology aims to do is stimulate many of these phosphenes across the visual field in a way that enables the patient to put together a picture of what they are looking at. The more electrodes an implant contains, the more phosphenes are capable of being generated, and the more detail a patient may be able to see.
Patients will need training to adapt to the visual information provided by the implant. Further, each and every patient’s experience with a bionic eye will be different. With time, training and patience, people will be able to use this visual information provided by the implant to be more independent and mobile.
We have created a Bionic Eye app to simulate the sort of vision a person using a bionic eye might experience.

How does the bionic eye work?

The bionic eye utilises an eyeglasses-mounted digital camera to capture the visual scene in front of the patient. This image is processed and then the data is sent to the implanted electrode array, which stimulates the surviving nerve cells in the patient’s retina. Electrical impulses from the retina then travel along the optic nerve to the vision processing parts of the brain and are decoded into vision.

24-electrode prototype

The 24-electrode device is an early prototype bionic eye that has now been implanted in three patients. A small lead wire extends from the back of the eye to a connector behind the ear. An external system is connected to this unit in the laboratory, allowing researchers to stimulate the implant in a controlled manner to study what patients are perceiving.
Testing with the device is helping researchers learn more about how the brain interprets visual information provided by the implant. Findings from patient tests are feeding back into development of the Wide-View and High-Acuity devices.

The Wide-View device

The retinal implant for the Wide-View device has an electrode array with 98 stimulating electrodes. This implant will be placed between the choroid and the sclera layers of the retina, protecting the retina from damage during insertion and helping to maintain the implant’s position. This device builds upon technologies that have been successfully employed in cochlear implants and uses materials with established biocompatibility and biostability. This device aims to restore vision to a degree that enables increased mobility and independence for patients.

A diagram showing the wide-view device, which consists of camera mounted on a pair of glasses, the data is processed and sent to implanted system via external wire, the implanted receiver passes signals onto retinal implant, electrical signals sent from retina via visual pathway to vision processing centres in the brain.

The High-Acuity device

The retinal implant for the second prototype bionic eye contains 1024 electrodes stimulating electrodes. The box to encapsulate the implant, and the electrodes themselves, will be made of stable, inert poly-crystalline doped diamond. Data and power will be transferred to the implant wirelessly. The High-Acuity device aims to restore vision to a level where patients will be able to recognise faces and read large print.

A diagram showing the high-acuity device, which consists of a camera mounted on a pair of glasses which wirelessly transmits data to impkant, retinal implant and processor stimulates retina, electrical signals sent from retina via visual pathway to vision processing centres in the brain.