Feeds

Living optical fibres found in the eye

Moving light past all those synapses

Bridging the IT gap between rising business demands and ageing tools

It is an old question: how does light make its way through all the retinal layers to finally strike the light sensitive cells at the back of the eye?

A group of researchers at the Paul-Flechsig-Institute of Brain Research, Universität Leipzig in Germany, thinks it has the answer. They have demonstrated that light is collected and funnelled through long cells called Müller cells. These work almost exactly like a fibre optic plate: a "zero-length window" that optical engineers can use to transmit an image without using a lens.

"Light has to go through all retinal layers to get to the photosensitive cells. This is not a problem for the octopus or the starfish which both have different eye structures. But it is a problem for all vertebrates," explains Andreas Reichenbach, who worked on the research.

"The layers in front of the rods and cones act as a diffusing screen. They have a half micron diameter which is roughly the same as the incoming light, so there must be lots of scattering. So we thought, could there be a way round this?

"We put unstained, living tissue on a microscope and focused through the layers. We found lots of light reflecting in synaptic and nerve layers, but with regular patterns of empty holes with no scattering."

Müller cell, transmitting light with no loss

The team then built up a cross section of the eye and found that the holes were in fact tubes, running all the way through. They were able to confirm that these were the Müller cells by running tests with lasers.

"Everyone thinks lasers are perfectly parallel, but this is not so," Reichenbach continues. "They do diverge. The Müller cells behave as a lens, and collect all the light without any loss, just like an optical plate."

But normal optical plates have simple bundles of optical fibres that collect and transmit the light. The researchers have discovered that the vertebrate eye has gone one step further and created a funnel shaped cell that allows more light to be collected at the surface of the eye.

The discovery doesn't have any direct medical applications, but it could pave the way for dramatic improvements in various pieces of sensing equipment.

"Nature is so clever," Reichenbach says. "This means there is enough room in the eye for all the neurons and synapses and so on, but still the müller cells can capture and transmit as much light as possible."

If the technique could be replicated with optical plates, it could mean engineers would be able to fit more into delicate sensors. "They could include lots of other things - computing elements for example," he adds.

The research, entitled "Müller cells are living optical fibers in the vertebrate retina" is published in the 30 April edition of the Proceedings of the National Academy of Sciences (PNAS). ®

Mobile application security vulnerability report

More from The Register

next story
Bad back? Show some spine and stop popping paracetamol
Study finds common pain-killer doesn't reduce pain or shorten recovery
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
World Solar Challenge contender claims new speed record
One charge sees Sunswift travel 500kms at over 100 km/h
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
SMELL YOU LATER, LOSERS – Dumbo tells rats, dogs... humans
Junk in the trunk? That's what people have
All those new '5G standards'? Here's the science they rely on
Radio professor tells us how wireless will get faster in the real world
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.