Related topics: brain · nerve cells · current biology · retina

The space rock that hit the moon at 61,000 kilometers an hour

Observers watching January's total eclipse of the Moon saw a rare event, a short-lived flash as a meteorite hit the lunar surface. Spanish astronomers now think the space rock collided with the Moon at 61,000 kilometres an ...

Nanotechnology makes it possible for mice to see in infrared

Mice with vision enhanced by nanotechnology were able to see infrared light as well as visible light, reports a study published February 28 in the journal Cell. A single injection of nanoparticles in the mice's eyes bestowed ...

Laser pioneers win Nobel Physics Prize

Three scientists on Tuesday won the Nobel Physics Prize, including the first woman to receive the prestigious award in 55 years, for inventing optical lasers that have paved the way for advanced precision instruments used ...

Fish-eye lens may entangle pairs of atoms

Nearly 150 years ago, the physicist James Maxwell proposed that a circular lens that is thickest at its center, and that gradually thins out at its edges, should exhibit some fascinating optical behavior. Namely, when light ...

Human eye capable of seeing 'ghosted' images

A team of researchers in the U.K. has found that the human eye and brain are together capable of seeing "ghosted" images. The researchers have published a paper describing their work on the arXiv preprint server.

Extinct monitor lizard had four eyes, fossil evidence shows

Researchers reporting in Current Biology on April 2 have evidence that an extinct species of monitor lizard had four eyes, a first among known jawed vertebrates. Today, only the jawless lampreys have four eyes.

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Eye

Eyes are organs that detect light, and send signals along the optic nerve to the visual and other areas of the brain[citation needed]. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in cnidaria, molluscs, chordates, annelids and arthropods.

The simplest "eyes", such as those in unicellular organisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms. From more complex eyes, retinal photosensitive ganglion cells send signals along the retinohypothalamic tract to the suprachiasmatic nuclei to effect circadian adjustment.

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