A recent study shows that blindness results in a permanent state of pain hypersensitivity, which is manifested, in particular, by a hypersensitivity to thermal stimuli.

 

One of the biological functions of acute pain is to prevent injury. Vision plays a critical role in this function, as it allows a person to detect and avoid potentially hazardous situations. But what happens in people who are blind? A recent study conducted in Italy and in Denmark indicates that they compensate for the absence of vision with a heightened vigilance for pain.

 

The three experiments conducted on blind people and people with normal vision consisted in measuring their pain threshold and the detection thresholds for warmth and cold perceptions. The results showed that, compared to sighted people, congenitally blind people had lower heat pain thresholds, found heat pain stimuli to be more painful and had increased sensitivity to cold pain stimuli.

 

“We have shown that the absence of vision from birth induces a hypersensitivity to painful stimuli, lending new support to a model of sensory integration of vision and pain processing,” explained Dr. Ron Kupers, from the University of Copenhagen, Denmark.

Sources:

http://www.sciencedaily.com/releases/2013/11/131101125413.htm

http://www.painjournalonline.com/article/S0304-3959(13)00275-3/abstract

Elias Benguigui, a well-known figure in Canada’s optical industry, particularly for his work with Perfect Optical, died during the night of November 10–11.

 

Elias Benguigui died at home, at the age of 83, just after he decided to embark on a well-deserved retirement. He had been having heart failure for a few months, but had regained his strength and started to exercise again. “He continued to be actively involved in Perfect Optical almost to the very end,” says his nephew, Adrian Maas. “Not even a year ago, we were still traveling around the world together to meet clients. Retirement just wasn’t for him!”

 

A native of Tangier, Morocco, Elias Benguigui initially resided in France after the Second World War, before coming to Canada to join his brother, Jacques, founder of Perfect Optical. Together, they worked long hours to make their company a success. “They would go all the way to Manitoba to present their products, though neither spoke a word of English,” says Adrian Maas. “But they didn’t care – they had good products to sell and they did it well.” In 1999, Elias Benguigui founded Superclip Canada with Adrian Maas.

 

Those who would like to pay their last respects can do so on Wednesday, November 13, at 3:00 p.m., at Paperman & Fils, located at 3888, Jean-Talon Street West, in Montreal.

 

A joint study by the University of Rochester in New York and Vanderbilt University in Tennessee suggests that fifty per cent of people can see and follow their own body movements in the dark.

 

The study was conducted on 129 participants from Rochester, Nashville and Seoul, a certain number of whom were synesthetes, or people who experience a blending of their senses which allows them, for instance, to see numbers or letters in different colours when they read.

 

During the experiment, participants were first asked to wear a blindfold which seemed to have holes in it. The researchers told them that they would see movements in low lighting. They were then given a blindfold without any holes and told that they would not see anything. In fact, none of the blindfolds had any holes that would allow participants to see. 

 

Participants were asked to wave their hands in front of their eyes and try to see the hand of a researcher who was also waving a hand. An eye-tracking device followed their eye movements. Although none of the participants was able to detect the movements of the researcher’s hand, half of them were able to see and follow the movements of their own hand, which means, according to the researchers, that hand movement sends a visual signal to the brain. Synesthetes were particularly skilled at seeing movements, one of whom was even able to see almost as well in the dark as in the light.

 

“This research shows that our own movements transmit sensory signals that also can create real visual perceptions in the brain, even in the complete absence of optical input,” explains Professor Duje Tadin, from the University of Rochester.

 

Source:

http://www.medicalnewstoday.com/articles/268281.php

 

A study conducted by Johnson & Johnson Vision Care has measured, for the first time ever, a coefficient of friction value on human corneal donor tissue.

 

The coefficient of friction is dependent on the type of buffer solution, but may not be dependent on donor age or on the time of death when measuring fresh corneal tissue, according to the study.

 

The study found that the coefficient of friction were 0.0134 in tear-mimicking solution, 0.0060 in tear-mimicking solution with phosphate buffer saline solution, 0.0144 in tear-mimicking solution with HEPES buffer and sodium chloride and 0.0153 in tear-like fluid with phosphate buffer saline solution.

 

“Now that we’ve measured the coefficient of friction value, additional investigation into the frictional behaviour of cornea tissue and its relation to contact lenses can be studied,” says Dr. Tawnya Wilson, principal research optometrist at VISTAKON^®. “This knowledge will ultimately lead to the development of better contact lenses that can mimic corneal properties and that can address end-of-day comfort for our patients.”

 

Source:

www.jnjvc.com

 

Researchers from Germany recently discovered the activation mechanism of one of the proteins that protect the eye against cataracts, laying the foundation for the development of new therapies.

 

The refractive power of the human eye depends on a highly concentrated protein solution. Two proteins in particular, ɑA-cristallin and ɑB-cristallin, ensure that other proteins do not turn into clumps over time. When this protective mechanism fails, the patient develops a cataract. 

 

“The great challenge in the analysis of these two crystallin types lies in their inordinate variety,” explains Johannes Buchner, professor for biotechnology at the Technical University of Munich. “These proteins exist as a mixture of very different forms, each comprising a variable number of subunits. This makes it very difficult to distinguish the individual structures from one to the other.”

 

In 2009, the German team had deciphered part of ɑB-cristallin, a molecule comprising 24 subunits, but found that in its idle form, it contributes little to the protection of the eye. It needed a trigger mechanism to activate it. This mechanism has now been uncovered.

 

These new insights provide a solid foundation for developing new therapeutic approaches. For instance, medication to treat cataracts could activate ɑB-cristallin, which would be in charge of clearing up cloudy lenses. This could eventually replace the need for surgery.

Source:

http://www.sciencedaily.com/releases/2013/10/131023141130.htm