Scientists have “reversed death” by bringing the eyes back to life.
Eyes taken from organ donors five hours after death reacted to light, while electrical activity seen only in the living was recorded.
The authors said this “begs the question of whether brain death, as currently defined, is truly irreversible.”
Brain death is when someone is no longer able to survive without life support, unable to breathe on their own.
It is considered irreversible and therefore a person is declared dead.
The science demonstrated by the team could be used to study other tissues of the central nervous system, such as the brain or the spine.
Lead author Dr Fatima Abbas, from the University of Utah Moran Eye Center, said: “We were able to awaken photoreceptor cells in the human macula, which is the part of the retina responsible for our vision. center and our ability to see fine detail and color.
“In eyes obtained up to five hours after the death of an organ donor, these cells responded to bright light, colored lights, and even very faint flashes of light.”
Part of death is the loss of neuron activity.
A controversial body of scientists has been researching how to reverse this neural activity and breathe life into the organs of those who have died.
The study, published in the journal Nature, follows Yale University bringing the brains of dead pigs to life in 2019.
Scientists were able to activate the blood circulation of the huge organs four hours after the pigs were slaughtered.
But what they failed to do, as those at the University of Utah did, was create communication between neurons.
Initially, the research team was able to revive light-sensitive neurons (photoreceptors) in the eye.
But the cells weren’t communicating with other cells in the retina – the tissue behind the eyes that collects light and sends imagery to the brain.
They discovered that the lack of oxygen was to blame.
And so, Dr. Frans Vinberg, assistant professor of ophthalmology and visual sciences, has found a way to restore oxygenation to the eyes of the organ donor, with some exciting findings.
The team saw electrical signals that are only in living eyes, called “b wave”.
This is the first b-wave recording made in the eyes of deceased people.
Dr Frans Vinberg, assistant professor of ophthalmology and visual sciences, said: “We were able to get the retinal cells to talk to each other, just as they do in the living eye.
“Previous studies have restored very limited electrical activity in the eyes of organ donors, but this has never been achieved in the macula, and never to the extent that we have now demonstrated.”
Dr Vinberg said: “The scientific community can now study human vision in a way that is simply not possible with laboratory animals.”
Professor Anne Hanneken, Scripps Research Associate, said: ‘So far it has not been possible to get the cells of all the different layers of the central retina to communicate with each other as they normally do in a living retina. .
“In the future, we may use this approach to develop treatments to improve vision and light signaling in eyes with macular diseases, such as age-related macular degeneration.”
This story originally appeared on The Sun and has been reproduced with permission.