Smart specs may replace guide dogs

Smart specs for the blind that could take the place of white canes and guide dogs may be available in two years, researchers have said.

The hi-tech glasses are designed to prevent “legally blind” individuals with a small degree of residual vision from bumping into objects.

They use tiny stereo cameras in the frames to project simplified images onto the lenses which become brighter the closer an object is.

From January next year the glasses will be tested in a series of trials involving 160 people with severely impaired sight in Oxford and London. Developer Dr Stephen Hicks, from Oxford University, said he hoped a finished model will be commercially available in around two years.

The cost is expected to be around £600 - slightly more than a smart phone. In comparison, a guide dog costs up to £30,000 to train.

Dr Hicks said the spectacles were designed as a navigational aid, not to restore lost vision.

"The glasses work using a pair of cameras that determine the distance of objects and we simply translate that into a light display," he said. "This is not restoring sight, but we can improve spatial awareness."

Around 300,000 people in the UK are registered as legally blind. Of these, 90% possess some residual vision allowing them to detect blurry shapes and differences between light and dark.

"The aim is to increase the independence of the hundreds of thousands of people who are visually impaired in the UK," said Dr Hicks.

The research was funded through the National Institute for Health Research Invention for Innovation (i4i) programme.

Engineering a Photo-Switch for Nerve Cells in the Eye and Brain

Chemists and vision scientists at the University of Illinois at Chicago have designed a light-sensitive molecule that can stimulate a neural response in cells of the retina and brain — a possible first step to overcoming degenerative eye diseases like age-related macular degeneration, or to quieting epileptic seizures.

Their results are reported online in the journal Nature Communications.

Macular degeneration, the leading cause of vision loss in people over 50, is caused by loss of light-sensitive cells in the retina — the rods and cones.

"The rods and cones, which absorb light and initiate visual signals, are the broken link in the chain, even though what we call the ‘inner cells’ of the retina, in many cases, are still potentially capable of function," says David Pepperberg, professor of ophthalmology and visual sciences in the UIC College of Medicine, the principal investigator on the study.

"Our approach is to bypass the lost rods and cones, by making the inner cells responsive to light."

Pepperberg and his colleagues are trying to develop light-sensitive molecules that — when injected into the eye — can find their way to inner retinal cells, attach themselves, and initiate the signal that is sent to the brain.

Human Eye Gives Researchers Visionary Design for New, More Natural Lens Technology

Drawing heavily upon nature for inspiration, a team of researchers has created a new artificial lens that is nearly identical to the natural lens of the human eye. This innovative lens, which is made up of thousands of nanoscale polymer layers, may one day provide a more natural performance in implantable lenses to replace damaged or diseased human eye lenses, as well as consumer vision products; it also may lead to superior ground and aerial surveillance technology.

This work, which the Case Western Reserve University, Rose-Hulman Institute of Technology, U.S. Naval Research Laboratory, and PolymerPlus team describes in the Optical Society’s (OSA) open-access journal Optics Express, also provides a new material approach for fabricating synthetic polymer lenses.

The fundamental technology behind this new lens is called “GRIN” or gradient refractive index optics. In GRIN, light gets bent, or refracted, by varying degrees as it passes through a lens or other transparent material. This is in contrast to traditional lenses, like those found in optical telescopes and microscopes, which use their surface shape or single index of refraction to bend light one way or another.

“The human eye is a GRIN lens,” said Michael Ponting, polymer scientist and president of PolymerPlus, an Ohio-based Case Western Reserve spinoff launched in 2010. “As light passes from the front of the human eye lens to the back, light rays are refracted by varying degrees. It’s a very efficient means of controlling the pathway of light without relying on complicated optics, and one that we attempted to mimic.”

Activating the ‘mind’s eye’ — sounds, instead of eyesight, can be alternative vision

Common wisdom has it that if the visual cortex in the brain is deprived of visual information in early infanthood, it may never develop properly its functional specialization, making sight restoration later in life almost impossible.

Scientists at the Hebrew University of Jerusalem and in France have now shown that blind people – using specialized photographic and sound equipment – can actually “see” and describe objects and even identify letters and words.

The new study by a team of researchers, led by Prof. Amir Amedi of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University and Ph.D. candidate Ella Striem-Amit, has demonstrated how this achievement is possible through the use of a unique training paradigm, using sensory substitution devices (SSDs).

SSDs are non-invasive sensory aids that provide visual information to the blind via their existing senses. For example, using a visual-to-auditory SSD in a clinical or everyday setting, users wear a miniature camera connected to a small computer (or smart phone) and stereo headphones.

The images are converted into “soundscapes,” using a predictable algorithm, allowing the user to listen to and then interpret the visual information coming from the camera. The blind participants using this device reach a level of visual acuity technically surpassing the world-agreed criterion of the World Health Organization (WHO) for blindness, as published in a previous study by the same group.

Brain May ‘See’ More Than the Eyes, Study Indicates

Vision may be less important to “seeing” than is the brain’s ability to process points of light into complex images, according to a new study of the fruit fly visual system currently published in the online journal Nature Communications.

University of Virginia researchers have found that the very simple eyes of fruit fly larvae, with only 24 total photoreceptors (the human eye contains more than 125 million), provide just enough light or visual input to allow the animal’s relatively large brain to assemble that input into images.

“It blows open how we think about vision,” said Barry Condron, a neurobiologist in U.Va.’s College of Arts & Sciences, who oversaw the study. “This tells us that visual input may not be as important to sight as the brain working behind it. In this case, the brain apparently is able to compensate for the minimal visual input.”

Condron’s graduate students, Elizabeth Daubert, Nick Macedonia and Catherine Hamilton, conducted a series of experiments to test the vision of fruit fly larvae after they noticed an interesting behavior of the animals during a different study of the nervous system. They found that when a larva was tethered to the bottom of a petri dish, other larvae were attracted to it as it wiggled attempting to free itself.

The animals apparently saw the writhing motion and were attracted to it, willingly traveling toward it. After several further experiments to understand how they sensed the motion, the researchers learned that the nearly blind animals likely were seeing the action, by wagging their heads side-to-side in a scanning motion to detect it, rather than by only hearing it or feeling vibration or by smelling the trapped larva. This was a surprise because of the very simple and limited vision of fruit fly larvae.

Foggy perception slows us down

Fog is an atmospheric phenomenon that afflicts millions of drivers every day, impairing visibility and increasing the risk of an accident. The ways people respond to conditions of reduced visibility is a central topic in vision research. It has been shown that people tend to underestimate speeds when visibility is reduced equally at all distances, as for example, when driving with a uniformly fogged windshield. But what happens when the visibility decreases as you look further into the distance, as happens when driving in true fog? New research by Paolo Pretto at the Max Planck Institute for Biological Cybernetics in Tübingen published in eLife, reveals that people tend to overestimate their speed when driving in fog-like conditions and therefore naturally tend to drive at a slower pace.

New Study Shows Effects of Prehistoric Nocturnal Life on Mammalian Vision

Since the age of dinosaurs, most species of day-active mammals have retained the imprint of nocturnal life in their eye structures. Humans and other anthropoid primates, such as monkeys and apes, are the only groups that deviate from this pattern, according to a new study from The University of Texas at Austin and Midwestern University.

The findings, published in a forthcoming issue of Proceedings of the Royal Society B, are the first to provide a large-scale body of evidence for the “nocturnal bottleneck theory,” which suggests that mammalian sensory traits have been profoundly influenced by an extended period of adaptation to nocturnality during the Mesozoic Era. This period lasted from 250 million years ago to 65 million years ago.

To survive in the night, mammals had a host of visual capabilities, such as good color vision and high acuity, which were lost as they passed through the nocturnal “bottleneck.”

(Image credit)

To bee an art critic, choosing between Picasso and Monet

Honeybees are also discerning art critics, according to scientists from UQ’s Queensland Brain Institute, the UQ School of Psychology and the Federal University of Sao Carlos, Brazil.

The study, published in the Journal of Comparative Physiology A, found honeybees had remarkable visual learning and discrimination abilities that extended beyond simple colours, shapes or patterns.

QBI researcher Dr Judith Reinhard said honeybees had a highly developed capacity for processing complex visual information, and could distinguish landscape scenes, types of flowers, and even human faces.

“This suggests that in spite of their small brain, honeybees have a highly developed capacity for processing complex visual information, comparable in many respects to vertebrates,” she said.

Dr Reinhard and her team investigated whether this capacity extended to complex images that humans distinguish on the basis of artistic style, including Impressionist paintings by Monet and Cubist paintings by Picasso.

“We were able to show that honeybees learned to simultaneously discriminate between five different Monet and Picasso paintings, and that they did not rely on luminance, colour, or spatial frequency information,” she said.

When presented with novel paintings of the same style, the bees demonstrated an ability to generalise, suggesting they could differentiate Monet from Picasso by extracting and learning the characteristic visual information inherent in each style.

“Our study suggests that discrimination of artistic styles is not a higher cognitive function that is unique to humans, but simply due to the capacity of animals – from insects to humans – to extract and categorise the visual characteristics of complex images,” Dr Reinhard said.