The ability of the eye of a fruit fly (Drosophila melanogaster) to respond to light depends on a delicate ballet that keeps the supply of light sensors called rhodopsin constant as photoreceptors turn on and off in response to light exposures, said researchers from Baylor College of Medicine (www.bcm.edu) and the Jan and Dan Duncan Neurological Research Institute (http://www.nri.texaschildrens.org/) at Texas Children’s Hospital in an article that appears online in the journal PLOS Biology (http://www.plosbiology.org/home.action). (108)

We appreciate the beauty of our great planet because of the visual pigments in our eyes. If one observe the eyes of different animals keenly, they exhibit enormous differences in size and function, for example a flatworm have small light sensitive spot, where as squids display camera like eyes as we do but with some differences. So this raises a question: How did eyes evolve in so many animals and why they look so different but still perform a similar function of vision?
The vast diversity observed in various animal eyes …

Visual opsins play an important role in photoreception. When light enters your eye it hits an opsin, which is present on the surface of photoreceptor cells.They mediate the first step in the visual signaling pathway, trigerring a series of chemical reactions, which converts the light into an electrical response and sends to brain.
Opsins belong to a large family of detector proteins, called the ‘G-protein coupled receptors’ (GPCRs). These GPCRs lie embedded in the plasma membrane by winding themselves through the membrane of the cell seven times. (392)

Palaeontologists have uncovered half-a-billion-year-old fossils demonstrating that primitive animals had excellent vision.
An international team led by scientists from the South Australian Museum and the University of Adelaide found the exquisite fossils, which look like squashed eyes from a recently swatted fly.
This discovery will be published tomorrow (Thursday 30 June 2011) in the prestigious journal Nature.
The lead author is Associate Professor Michael Lee from the South Australian Museum and the University of Adelaide’s School of Earth & Environmental Sciences.
Compound Eyes
Modern insects and crustaceans have “compound eyes” consisting of hundreds or even …

Scientists today reported that the tiny light-sensing cells known as rods have been clearly and directly imaged in the living eye for the first time. Using adaptive optics (AO), the same technology astronomers use to study distant stars and galaxies, scientists can see through the murky distortion of the outer eye, revealing the eye’s cellular structure with unprecedented detail. This innovation, described in two papers in the Optical Society’s (OSA) open access journal Biomedical Optics Express, will help doctors diagnose degenerative eye disorders sooner, leading to quicker intervention and more …

Remember in December last year we had a special issue from Evolution: Education and Outreach dealing with the aspect related to evolution of eyes.That special issue was edited by T. Ryan Gregory, who also wrote the Introduction to the issue.
Now there is another journal “Philosophical Transactions of the Royal Society B” has come out with some excellent collection of papers on “The evolution of phototransduction and eyes”,edited by some very well known scientists Trevor D. Lamb, Detlev Arendt, and Shaun P. Collin. (85)

The brownsnout spookfish (Dolichopteryx longipes)is a deep sea dweller and hit the headlines across the scientific field for the way it sees the outer world. Deep oceans hold many secrets and spookfish with four eyes is out there competing with the very best for the top spot.Recent research has shown that it is the first vertebrate to use mirror instead of lens to see the world around in deep ocean. In fact these spook fishes does not have four eyes but has just two eyes, each eye has two parts, …