Vision

The human eye is optimized to have good color vision at day and high sensitivity at night. 

But until recently it seemed as if the cells in the retina were wired the wrong way round, with light traveling through a mass of neurons before it reaches the light-detecting rod and cone cells.

New research presented at a meeting of the American Physical Society has uncovered a remarkable vision-enhancing function for this puzzling structure.

We have two eyes and each differ in their optical properties - you can easily tell by placing a hand over each and seeing the difference.

As a result of the fits and starts and do-overs in evolution that got us eyes, our vision system results in a blur projected in each retina and then the visual system calibrates itself to give us a clear picture. In the past, researchers had people where glasses where images were upside down. Eventually, our brains compensated and the images were correct - until people took off the glasses. 
A dress that seems to be different colors to different people has all the Internet intrigued - and that's a good thing. It's a good way to understand science and psychology.

There are two hypotheses as to why people see dramatically different things; one is that our brains are constantly being bombarded by information and so we end up making a lot of assumptions and interpretations based on parameters. If you are looking up close at something and infer a blue background, you see the dress differently than people who assume it has an artificial light background, like yellow.


An estimated 285 million people are visually impaired worldwide and age-related macular degeneration alone is the leading cause of blindness among older adults. There may be some new hope, in the form of prototype telescopic contact lenses. 

Eric Tremblay from EPFL in Switzerland says the first iteration of the telescopic contact lens--which magnifies 2.8 times--was announced in 2013. Since then the scientists behind the DARPA-funded project have been fine-tuning the lens membranes and developing accessories to make the eyewear smarter and more comfortable for longer periods of time, and thus more usable in every day life.

Tony Angelotti stunt doubling Johnny Depp in the first ‘Pirates of the Caribbean’ movie. Image credit: Courtesy of Tony Angelotti

By:
Emilie Lorditch, Inside Science 

According to some papers, human echolocation is another "sense," working in tandem with hearing and touch to deliver information to people with visual impairment.

A new paper adds evidence for the vision-like qualities of echolocation in blind echolocators - by wrongly judging how heavy objects of different sizes felt.

The experiment, conducted by psychologist Gavin Buckingham of Heriot-Watt University in Scotland and colleagues at the Brain and Mind Institute at Western University in Canada, demonstrated that echolocators experience a "size-weight illusion" when they use their echolocation to get a sense of how big objects are, in just the same way as sighted people do when using their normal vision.


The evolution of trichromatic color vision in humans occurred by first switching from the ability to detect UV light to blue light between 80 and 30 million years ago and then by adding green-sensitivity(between 45-30 million years ago to the preexisting red-sensitivity in the vertebrate ancestor, according to Shozo Yokoyama et al. in PLOS Genetics.


The retina is the neural tissue in the back of the eye that initiates vision. It is responsible for receiving light signals and converting them into neurologic signals, which are then transmitted via the optic nerve to the brain so that we can see.

Mutations that disrupt vision by damaging the retina and optic nerve have been identified in more than 200 genes. This genetic diversity made genetic diagnostic testing difficult until the recent development of high throughput genomic techniques.


The Six Billion Dollar Man is getting a little bit closer, not just to movie theaters, but in real life. 

A new development toward a prosthetic retina could help counter conditions that result from retinal degeneration, a life-altering health issue for many people, especially as they age.


Congratulations to Masayo Takahashi, MD, PhD, the winner of the 2014 Stem Cell Person of the Year Award.