* Astronomy

Blobrana · L

RE: Eye

Blobrana · L

Shape of eye's 'light pipes' is key to colour sorting

Physicists have pinned down precisely how pipe-shaped cells in our retina filter the incoming colours.
These cells, which sit in front of the ones that actually sense light, play a major role in our colour vision that was only recently confirmed.
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Blobrana · L

New study sheds light on how and when vision evolved

Opsins, the light-sensitive proteins key to vision, may have evolved earlier and undergone fewer genetic changes than previously believed, according to a new study from the National University of Ireland Maynooth and the University of Bristol published today in Proceedings of the National Academy of Sciences (PNAS) .
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Blobrana · L

Colour is one of our simplest sensations... even jellyfish see lightness and they do not have a brain. And yet to explain lightness, and colour more generally, is to explain how and why we see what we do.
The first thing to remember is that colour does not actually exist... at least not in any literal sense. Apples and fire engines are not red, the sky and sea are not blue, and no person is objectively "black" or "white".
What exists is light. Light is real.
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Blobrana · L

New fossils provide evidence of powerful eyes

Palaeontologists have uncovered half-a-billion-year-old fossils demonstrating that primitive animals had excellent vision.
An international team led by scientists from the South Australian Museum and the University of Adelaide found the exquisite fossils, which look like squashed eyes from a recently swatted fly.
This discovery will be published today in the prestigious journal Nature.
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New Fossils Demonstrate That Powerful Eyes Evolved in a Twinkling

Blobrana · L

Magnetoreception

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RE: Eye

Blobrana · L

There is more to the eye than rods and cones - the discovery of a third photoreceptor is rewriting the visual rulebook.

Russell Foster remembers his first human subject, an 87-year-old woman, as she sat in a dark room facing a backlit pane of frosted glass. A genetic disorder had destroyed the light-sensing rod and cone cells in her eyes, leaving her blind for the past 50 years. She was convinced that she would see nothing. But as the wavelength of light in the room shifted to blue, she reported - after some hesitation - a sort of brightness.
Foster and his collaborators had done nothing to treat the woman's blindness. Instead, her awareness of light owed itself to a class of light-sensitive cells discovered in 2002.
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Blobrana · L

It's hard to miss the huge eye of a squid. But now it appears that certain squids can detect light through an organ other than their eyes as well.
That's what researchers at the University of Wisconsin-Madison report in the current issue (June 2) of the Proceedings of the National Academy of Sciences.
The study shows that the light-emitting organ some squids use to camouflage themselves to avoid being seen by predators - usually fish sitting on the ocean floor - also detects light.
The findings may lead to future studies that provide insight into the mechanisms of controlling and perceiving light.

"Evolution has a 'toolkit' and when it needs to do a particular job, such as see light, it uses the same toolkit again and again. In this case, the light organ, which comes from different tissues than the eye during development, uses the same proteins as the eye to see light" - lead author Margaret McFall-Ngai, a professor of medical microbiology and immunology at the UW-Madison School of Medicine and Public Health (SMPH).

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Blobrana · L

Spookfish