When a total solar eclipse comes to the Dallas-Fort Worth area on April 8, and the moon starts to cover the sun in the sky, it may feel safe to sneak a peek without eclipse glasses. But experts say that staring at the sun ...
Space Exploration
Feb 5, 2024
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5
New findings in color vision research imply that humans can perceive a greater range of blue tones than monkeys do.
Plants & Animals
May 1, 2023
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194
Pick an object in front of you—a teacup, for example—and fix your gaze on it. You may think that you're keeping your eyes still, but you're not: Your eyes are frequently moving unbeknownst to you, making tiny involuntary ...
Plants & Animals
Oct 27, 2022
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29
Devices that can automatically detect and recognize moving objects have numerous valuable applications, for instance, enhancing remote environmental monitoring. Most existing motion detection and recognition (MDR) technologies ...
A research team from the Centre for Organismal Studies (COS) of Heidelberg University has demonstrated that complex retinal tissue can be cultured in a Petri dish from embryonic stem cells of bony fish. Until now, stem cells ...
Cell & Microbiology
Sep 3, 2021
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196
When we fixate an object, its image does not appear at the place where photoreceptors are packed most densely. Instead, its position is shifted slightly nasally and upwards from the cellular peak. This is shown in a recent ...
Evolution
Aug 2, 2021
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387
During the course of evolution, animals have adapted to the particular demands of their local environments in ways that increased their chances of survival and reproduction. This is also true of diverse aspects of the sensory ...
Plants & Animals
Jul 2, 2021
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27
To see—and survive—at night, some coral fish have developed visual adaptations that are similar to those of their cousins living in the ocean's darkest depths, new research shows.
Plants & Animals
Feb 9, 2021
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14
In a study published online in the Journal of Cell Biology on July 23, the researchers from Dr. He Jie's Lab at the Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology of the Chinese ...
Cell & Microbiology
Jul 23, 2020
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2
One of the most remarkable characteristics of the vertebrate eye is its retina. Surprisingly, the sensitive portions of the photoreceptor cells are found on the hind side of the retina, meaning that light needs to travel ...
Biotechnology
Feb 25, 2020
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117
The vertebrate retina is a light sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centers of the brain through the fibers of the optic nerve.
In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS).. It is the only part of the CNS that can be imaged non-invasively in the living organism.
The retina is a complex, layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the photosensitive ganglion cell, is important for reflexive responses to bright daylight.
Neural signals from the rods and cones undergo complex processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light.
This text uses material from Wikipedia, licensed under CC BY-SA
