News tagged with eye

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

This Fourth of July, leave fireworks to professionals

Thousands of accidents each year underscore the danger of fireworks. In 2014, 11 people died and an estimated 10,500 were treated in emergency departments for fireworks-related injuries in the U.S. Statistics show the typical ...

Jun 30, 2016
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Music for the eyes

Having relaxing music played just before eye surgery leads to patients feeling less anxiety and requiring less sedation, concludes a study presented at Euroanaesthesia 2016 (London, 27-30 May). The study is by Dr Gilles Guerrier, ...

May 28, 2016
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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.

This text uses material from Wikipedia, licensed under CC BY-SA

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