Amazing Medical Inventions: The Bionic Eye – A hope for blinds

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285 million people are estimated to be visually impaired worldwide: 39 million are blind and 246 have low vision. 82% of people living with blindness are aged 50 and above. Globally, uncorrected refractive errors are the main cause of moderate and severe visual impairment but good news is that 80% of all visual impairment can be prevented or cured.

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Reading the statistics it’s no surprise that scientist are going haywire thinking of novel ways to impair sight. One such try is the invention of a bionic eye. The scientists working on bionic eye have one common goal: to develop technology that’s as effective for visual disabilities as cochlear implants have become for auditory ones. But different scientists’ methods for achieving this vary. What’s more, bionic eye technology is still in its infancy compared with cochlear implants for hearing loss.

Several bionic eye implants are in development, but currently only one is available in the United States, and it is suitable only for blindness caused by specific eye diseases. However, as research continues, more and more people may soon benefit from high-tech bionic eyes.

What gives me huge pleasure is the fact that Bionic eye was invented by A Pakistani-American who then won the US highest award for technology achievement. Mark Humayun received the prestigious National Medal of Technology and Innovation from President Obama.

Mark Humayun

Mark Humayun

It is a “testament to American ingenuity,” announced Obama. Mark Humayun has developed Argus II, commonly known as the ‘bionic eye’. It restores vision to most blind people. By merging medical science and engineering, Mark’s invention is a miracle for people suffering from inherited retinal degenerative disease that leads to blindness in old age. “A camera mounted on special glasses sends a signal to an electronic receiver with electrodes that are implanted in and around the eye. The electrodes send signals to the retina that stimulate the retina and then these retinal impulses travel through the optic nerve to the brain where they are interpreted as images.”

A bionic eye is not the same thing as a prosthetic eye. Prosthetic eyes (also called “glass eyes” or “artificial eyes”) replace the physical structure and appearance of an eye that must be removed due to trauma, pain, disfigurement or disease. Bionic eye implants, on the other hand, work inside the existing eye structures or in the brain. They are designed to achieve functional vision goals — as opposed to physical, cosmetic ones.

Just as there is no single cause for blindness, there’s likewise no one cure. To determine whether a bionic eye could help you see, it’s important to know the reason(s) for your vision loss.

The process of sight begins when light enters the eye. The cornea and lens focus light onto the retina at the back of the eyeball. Light-sensitive cells in the retina then convert the focused light into electrical energy, which is transported to the brain via the optic nerve.

In blind people, part of this process doesn’t work. In some cases, the cornea or lenses are damaged or diseased, or the retina can’t perceive light. In others, the signal is lost somewhere along the visual pathway in the brain.

The Argus II Retinal Prosthesis System consists of a tiny eyeglasses-mounted camera and a transmitter that wirelessly sends signals to an electrode array that is implanted onto the damaged retina of a blind person.
The Argus II Retinal Prosthesis System consists of a tiny eyeglasses-mounted camera and a transmitter that wirelessly sends signals to an electrode array that is implanted onto the damaged retina of a blind person.

Different bionic eye models take aim at different target areas in the visual pathway. Currently, retinal implants are the only approved and commercially available bionic eyes, though cornea transplants and cataract surgery can replace the cornea and lens if these structures are clouded or are incapable of focusing light for other reasons.

Who Can Benefit From Currently Available Bionic Eyes?

The Argus II has been used to restore some level of visual perception to hundreds of individuals with severe retinitis pigmentosa — a disease that affects one in 5,000 people. The Argus II also is being tested for people with a much more common condition, age-related macular degeneration.

How can Pakistanis benefit?

Pakistanis with retinal blindness especially Retinitis Pigmentosa can benefit greatly. The device would have to be either approved in Pakistan by the government or the patients would have to travel to one of the countries in which the device is already approved.

Testifying to Mark Humayun’s genius is Farid Hassan, former Chairman of Bausch and Lomb, a global leader in eye care. This helped improve the access and affordability of cataract surgery. By simplifying procedures, Mark worked to make cataract surgery accessible to hundreds of millions of potential seniors around the world. “He’s not only a compassionate surgeon, he’s a passionate innovator who keeps driving forward with cutting edge science,” says Hassan. “My personal admiration for Mark went up when I saw him fearless in mobilising disruptive innovation [Disruptive innovation is the introduction of new technologies in an effort to promote change and gain advantage over the competition] to destroy the terror of blindness.”

For Mark, asserts Hassan, his first duty is to help patients waiting to be cured. “He does not make them wait too long … so, the biggest descriptor for Mark is that he’s a humanitarian!”

How Retinal Implants Restore Sight

The Argus II is a two-part system: It includes a small camera that is mounted on a pair of eyeglasses and a tiny array of electrodes that is implanted in the back of the eye, on the retina.

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Whatever the camera sees is converted into signals that are transmitted wirelessly to the retinal implant. In response, the chip’s electrodes stimulate the retinal cells, causing them to send the incoming information to the optic nerve so it can be processed by the brain.

Limitations Of Bionic Eyes

Although the Argus II system enables people to discern light, movement and shapes, it does not yet restore sight to the extent some might hope. This limitation is largely due to the fact that the current implant has only 60 electrodes. To see naturally, you’d need about a million.

However, some Argus II users can function well enough to read large-print books and cross the street on their own. And the company plans to add more electrodes in future models.

Another limitation of the current Argus II Retinal Prosthesis System is that it doesn’t enable users to perceive colors. And it’s expensive — costs associated with the device and procedure add up to nearly $150,000 and may or may not be covered by medical insurance.

The Future Of Bionic Eyes

Future iterations of the Argus II system will likely feature advanced implants with higher numbers of electrodes that are capable of producing sharper, more functional vision for people who are blind from retinitis pigmentosa and other retinal diseases, including macular degeneration. It’s possible future implants may also be able to produce some degree of color vision.

In addition to Mark’s bionic eye, researchers elsewhere are testing devices with even more electrodes, as well as devices that bypass the retina and stimulate the brain directly.

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