Assistant Professor of Cognitive Science at Rensselaer Polytechnic Institute Mark Changizi says that actions like catching a football or easily moving through a room full of people requires something more than quickly responding to a situation — it requires our ability to foresee the future.

It takes our brain nearly one-tenth of a second to translate the light that hits our retina into a visual perception of the world around us. While a neural delay of that magnitude may seem minuscule, imagine trying to catch a ball or wade through a store full of people while always perceiving the very recent (one-tenth of a second prior) past. A ball passing within one meter of you and traveling at one meter per second in reality would be roughly six degrees displaced from where you perceive it, and even the slowest forward-moving person can travel at least ten centimeters in a tenth of a second.

For the first time, a study combines measurements of abnormalities in the eye with models for assessing how well an individual can see, meaning it may be possible to program a machine to automatically produce prescriptions for corrective lenses.

The model for predicting visual clarity — based on measurements taken by today’s highly accurate aberrometers — could also enable surgeons to more accurately assess and correct the vision of patients undergoing lasik or refractive surgery.

New technology in aberrometers means ophthalmologists and others can accurately measure refractive error and other abnormalities in the eye’s optics. But these instruments cannot use these measurements to predict visual acuity, or how well a person can actually see. Usually, ophthalmologists and optometrists rely on a patient’s ability to identify characters on an eye chart to determine visual clarity.

The vision system used to process color is separate from that used to detect motion, according to a new study by researchers at New York University’s Center for Developmental Genetics and in the Department of Genetics and Neurobiology at Germany’s University of Würzburg.

The findings run counter to previous scholarship that suggested motion detection and color contrast may work in tandem.

Whether motion vision uses color contrast is a controversial issue that has been investigated in several species--from insects to humans. In human vision, it had been widely believed that color and motion were processed by parallel pathways. More recently, however, the complete segregation of motion detection and color vision came into question.

New research suggests that humans are not as fooled as they seem when viewing visual illusions.

Ben-Gurion University of the Negev Psychologist Tzvi Ganel, writing in the March issue of Psychological Science, says we process images in two very distinct ways. He and his colleagues presented research participants with the “Ponzo” illusion, an image common in psychological research that makes two objects that are similar in length appear drastically different. They then hooked participants’ index finger and thumb to computerized position tracking equipment and asked them to grasp the objects with their fingers.

Just picture the scene: you’re at a cocktail party, talking to someone you would like to get to know better but the background noise is making it hard to concentrate. Luckily, humans are very gifted at listening to someone speaking while many other people are talking loudly at the same time. This so-called cocktail-party-phenomenon is based on the ability of the human auditory system to decompose the acoustic world into discrete objects of perception.

It was originally believed that the major acoustic cue used by the auditory system to solve this task was directional information of the sound source, but even though localisation of different sound sources with two ears improves the performance, it can be achieved monaurally, for example in telephone conversations, where no directional information is available.

Why is it difficult to pick out even a familiar face in a crowd? We all experience this, but the phenomenon has been poorly understood until now.

The results of a recent study may have implications for individuals with face-recognition disorders and visual-attention related ailments — and eventually could help scientists develop an artificial visual system that approaches the sophistication of human visual perception.

The study is part of a recently completed Journal of Vision special issue titled “Crowding: Including illusory conjunctions, surround suppression, and attention”. “Crowding” is a failure to recognize an individual object in a cluttered environment. It may be due to one of the shortcuts our brains use to help us make sense of the vast amount of visual information we take in every second.

Laser surgery to correct vision problems has been in use since the early 1990s. Photorefractive Keratotomy (PRK) is typically used to correct low to moderate myopia, while laser in-situ keratomileusis (LASIK) is preferred for high myopia corrections. Although over 18 million LASIK procedures have been performed worldwide, there is still some controversy regarding the maximum correction possible and efficacy with this technique.

In an article published in the January 2008 issue of the American Journal of Ophthalmology, researchers from Miguel Hernandez University, Medical School, Alicante, Spain; and Ankara University School of Medicine, Ankara, Turkey; report on a study of high myopia patients ten years after LASIK surgery. The findings show that LASIK for myopia over -10 diopter (10 D) is a safe and effective procedure in the long-term.

In a study of more than 6,000 Los Angeles-area children – the largest study of its kind – researchers at the Keck School of Medicine of the University of Southern California (USC) found that both strabismus (commonly known as cross-eyed or wall-eyed) and amblyopia (often referred to as lazy eye) were more prevalent in older children than in younger children. The study was in the journal Ophthalmology.

The population for this first phase of the Multi-Ethnic Pediatric Eye Disease Study (MEPEDS) was composed equally of African-American and Hispanic youngsters, ages six months to six years, who reside in the Los Angeles County community of Inglewood. The overall prevalence of strabismus was 2.5%; while this finding remained constant regardless of gender or ethnicity, prevalence trended upward with increasing age. The overall prevalence of amblyopia, which was 2.6% in both ethnic groups, similarly trended upward with age, although researchers concluded that this trending stabilizes by three years of age. As with strabismus, researchers found no difference when amblyopia results were stratified by gender.

Two transporters that deliver alternative energy sources to the eye may help delay retinal damage that can occur in diabetes, researchers say.

The transporters, SMCT1 and SMCT2, can circumvent the eye’s protective blood-retinal barrier, delivering energy sources lactate and ketone bodies to a healthy eye, says Dr. Pamela Martin, biochemist at the Medical College of Georgia.

In diabetes, characterized by plenty of glucose but the inability of cells to use it, the retina may turn to those alternate sources for survival.

“Glucose is your primary energy source,” says Dr. Martin. “But in diabetes, the retina undergoes a lot of stress, there is oxidative damage and a lot of other things going on. These transporters, we believe, may be instrumental in bringing in additional substrates which the cells can use for energy to try and prevent death.”

Diabetic retinopathy, the leading cause of blindness in working-age adults, results in death of retinal neurons, at least in part because glucose availability is compromised for this high-energy-consuming tissue, says Dr. Martin.

She suspects the two transporters work harder in diabetes to increase levels of lactate and ketones bodies, which may help explain why diabetes’ impact on the eye may go undiagnosed for years. “I think what fascinates me so much about the eye is you can have diabetes for more than 20 years before you or your doctor realize that you have diabetic retinopathy,” says Dr. Martin.

A five-minute eye exam might prove to be an inexpensive and effective way to gauge and track the debilitating neurological disease multiple sclerosis, potentially complementing costly magnetic resonance imaging to detect brain shrinkage - a characteristic of the disease’s progression.

A Johns Hopkins-based study of a group of 40 multiple sclerosis (MS) patients used a process called optical coherence tomography (OCT) to scan the layers of nerve fibers of the retina in the back of the eye, which become the optic nerve. The process, which uses a desktop machine similar to a slit-lamp, is simple and painless. The retinal nerve fiber layer is the one part of the brain where nerve cells are not covered with the fat and protein sheathing called myelin, making this assessment specific for nerve damage as opposed to brain MRI changes, which reflect an array of different types of tissue processes in the brain.