Light affects us even without impinging on our awareness. In 1995, Charles Czeisler and colleagues at Harvard Medical School described people who lacked visual perception due to retinal degeneration, but nevertheless responded to light subconsciously — despite being blind, their melatonin level was suppressed, and they appeared to synchronize their circadian clock with the solar day. Across the pond at Oxford, Russell Foster and colleagues were finding the same in mice, and learned that these responses began in the eye.
These discoveries spurred an intense research effort that continues to this day. What system confers subconscious sight, and how does it differ from the system that generates visual experience? …
Some kinds of vision loss are reversible: Lucentis and Avastin can restore some visual acuity in macular degeneration, and gene therapy in the eye has had success in genetic forms of blindness like Leber’s hereditary neuropathy, affecting light receptors in the retina. But when the optic nerve is damaged – from a traumatic injury or from glaucoma — all bets are off. The eyes may take in visual information, but it can’t get to the brain. It’s the end of the road.
Larry Benowitz, PhD, and other neurobiologists at Boston Children’s Hospital and elsewhere have tried for years to rebuild that road. Regeneration of the optic nerve, and in the central nervous system in general, was once thought impossible. But through patient tinkering to coax natural growth signals and silence growth-inhibiting signals, neurons in the retina – known as retinal ganglion cells — began to grow a bit into the optic nerve. Then a bit more.
In a 2010 paper, Benowitz’s team combined their top three interventions, and showed a synergistic effect – the greatest growth of optic nerve fibers (axons) to date. But no one had been able to demonstrate recovery of vision after severe optic nerve damage – until now. …
What if blind eyes could see? What does that mean?
That’s the question neuroscientist Pawan Sinha and his team at MIT has begun to answer in a uniquely humanitarian and scientific endeavor.
Project Prakash (named for the Sanskrit word for “light”) intended, at first, to cure blind children in India. It’s a noble effort, given that India has the world’s highest population of blind people, less than half of whom survive to their third birthday and less than one percent of whom are employable.
Sinha’s team screened 20,000 blind Indian children and treated 700 of them for correctable problems such as cataracts. As Sinha recounted at last month’s One Mind for Research forum, these 700 children now can see.
Omega-3’s are emerging superheroes in the nutrition world. Over two decades ago, scientists noticed that Greenland Eskimos had very low rates of coronary heart disease compared to Western populations. Their secret, it turned out, was eating fish—particularly, fatty fishes like salmon that contain a lot of omega-3 fatty acids.
An avalanche of studies have since demonstrated the cardiovascular health benefits of omega-3 fatty acids, also found in flax seeds and walnuts, as well as suggesting benefits in combating depression, rheumatoid arthritis and some types of cancer, and in boosting cognitive function.
And now comes more evidence that they can prevent blindness. …
When my parents told me I should walk around with my right eye patched like a pirate—on regular days, not just Halloween—I wondered if they were joking. They weren’t: those really were the doctor’s orders.
As a child, I had amblyopia, or “lazy eye”: my left eye had much poorer vision than my right eye. The eye itself was fine, but my brain wasn’t processing information coming from it. The plan was, by patching the “good” eye, to force my brain to use inputs from the amblyopic eye. …