This article is about the organ. For the human eye, see Human eye. For other uses, see Eye (disambiguation).
"Eyeball", "Eyes", and "Ocular" redirect here. For other uses, see Eyeball (disambiguation), Eyes (disambiguation), and Ocular (disambiguation).
Eye
Schematic diagram of the human eye en.svg
Human eye
Krilleyekils.jpg
Compound eye of Antarctic krill
Details
System Nervous
Identifiers
Latin oculus
TA A15.2.00.001
A01.1.00.007
FMA 75665
Anatomical terminology
[edit on Wikidata]
Eyes are the organs of vision. They detect light and convert it into electro-chemical impulses in neurons. In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system.[1] Image-resolving eyes are present in molluscs, chordates and arthropods.[2]
The simplest "eyes", such as those in microorganisms, do nothing but detect whether the surroundings are light or dark, which is sufficient for the entrainment of circadian rhythms.[3] From more complex eyes, retinal photosensitive ganglion cells send signals along the retinohypothalamic tract to the suprachiasmatic nuclei to effect circadian adjustment and to the pretectal area to control the pupillary light reflex.