Search results
Results from the WOW.Com Content Network
Apposition eyes work by gathering a number of images, one from each eye, and combining them in the brain, with each eye typically contributing a single point of information. The typical apposition eye has a lens focusing light from one direction on the rhabdom, while light from other directions is absorbed by the dark wall of the ommatidium.
Help; Learn to edit; Community portal; Recent changes; Upload file; Special pages
Humans have two eyes, situated on the left and the right of the face. The eyes sit in bony cavities called the orbits, in the skull. There are six extraocular muscles that control eye movements. The front visible part of the eye is made up of the whitish sclera, a coloured iris, and the pupil. A thin layer called the conjunctiva sits on top of ...
The visual system is the physiological basis of visual perception (the ability to detect and process light).The system detects, transduces and interprets information concerning light within the visible range to construct an image and build a mental model of the surrounding environment.
The retina (from Latin rete ' net '; pl. retinae or retinas) is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs.The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual ...
When Shh is inhibited during development, the domain of expression for Pax6 is expanded and the eyes fail to separate causing cyclopia. [14] Overexpression of Shh causes a loss of eye structures. Retinoic acid generated from vitamin A in the retina plays an essential role in eye development as a secreted paracrine signal which restricts ...
A starling, for example, has laterally placed eyes to cover a wide field of view, but can also move them together to point to the front so their fields overlap giving stereopsis. A remarkable example is the chameleon, whose eyes appear as if mounted on turrets, each moving independently of the other, up or down, left or right. Nevertheless, the ...
Cones work at high light levels (during the day but also during driving at night in the headlamp spotlight). Rods take over at twilight and night. The y-axis has logarithmic scaling. A minor mechanism of adaptation is the pupillary light reflex, adjusting the amount of light that reaches the retina very quickly by about a factor of ten. Since ...