Bio · Human-ities · Science · Technology · Vital-Edible-Health

Biologists grow human-eye precursor from stem cells

A stem-cell biologist has had an eye-opening success in his latest effort to mimic mammalian organ development in vitro. Yoshiki Sasai of the RIKEN Center for Developmental Biology (CBD) in Kobe, Japan, has grown the precursor of a human eye in the lab.

The structure, called an optic cup, is 550 micrometres in diameter and contains multiple layers of retinal cells including photoreceptors. The achievement has raised hopes that doctors may one day be able to repair damaged eyes in the clinic. But for researchers at the annual meeting of the International Society for Stem Cell Research in Yokohama, Japan, where Sasai presented the findings this week, the most exciting thing is that the optic cup developed its structure without guidance from Sasai and his team.

Excerpt of an article written by David Cyranoski, at Nature. Continue HERE

Bio · Human-ities · Performativity · Science · Technology · Vital-Edible-Health

Dreaming in color after 20 years: Eye implant restores vision to blind patient

It was the ‘magic moment’ that released Chris James from ten years of blindness.

Doctors switched on a microchip that had been inserted into the back of his eye three weeks earlier.

After a decade of darkness, there was a sudden explosion of bright light – like a flash bulb going off, he says.

Now he is able to make out shapes and light. He hopes his sight – and the way his brain interprets what the microchip is showing it – will carry on improving.

Mr James, 54, is one of two British men who have had their vision partly restored by a pioneering retina implant.

The other, Robin Millar, one of Britain’s most successful music producers, says he has dreamed in color for the first time.

Both had lost their vision because of a condition known as retinitis pigmentosa, where the photoreceptor cells at the back of the eye gradually cease to work.

Their stories bring hope to the 20,000 Britons with RP – and to those with other eye conditions such as advanced macular degeneration which affects up to half a million.

Mr James had a ten-hour operation to insert the wafer-thin microchip in the back of his left eye at the Oxford University Eye Hospital six weeks ago. Three weeks later, it was turned on.

Mr James, who lives in Wroughton, Wiltshire, with his wife Janet, said of his ‘magic moment’: ‘I did not know what to expect but I got a flash in the eye, it was like someone taking a photo with a flashbulb and I knew my optic nerve was still working.’

The external device that allows chip pairs to process images.

Written by y Jenny Hope (Hopeful article by the way) at the Daily Mail. Continue article HERE

Images via Daily Mail, and The Telegraph

Bio · Science

The Eye Limits the Brain’s Learning Potential

The concept of a critical period for visual development early in life during which sensory experience is essential to normal neural development is now well established. However recent evidence suggests that a limited degree of plasticity remains after this period and well into adulthood. Here, we ask the question, “what limits the degree of plasticity in adulthood?” Although this limit has been assumed to be due to neural factors, we show that the optical quality of the retinal image ultimately limits the brain potential for change. We correct the high-order aberrations (HOAs) normally present in the eye’s optics using adaptive optics, and reveal a greater degree of neuronal plasticity than previously appreciated.

Read this scientific report at Nature