Ad
related to: retina anatomy eye
Search results
Results From The WOW.Com Content Network
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 perception.
The macula (/ˈmakjʊlə/) [1] or macula lutea is an oval-shaped pigmented area in the center of the retina of the human eye and in other animals. The macula in humans has a diameter of around 5.5 mm (0.22 in) and is subdivided into the umbo, foveola, foveal avascular zone, fovea, parafovea, and perifovea areas.
The retina has a static contrast ratio of around 100:1 (about 6.5 f-stops). As soon as the eye moves rapidly to acquire a target , it re-adjusts its exposure by adjusting the iris, which adjusts the size of the pupil. Initial dark adaptation takes place in approximately four seconds of profound, uninterrupted darkness; full adaptation through ...
M cones, the second most common type, respond most strongly to yellow to green medium-wavelength light, peaking at 530 nm, and make up about a third of cones in the human eye. S cones respond most strongly to blue short-wavelength light, peaking at 420 nm, and make up only around 2% of the cones in the human retina.
In the visual system, retinal, technically called retinene 1 or "retinaldehyde", is a light-sensitive molecule found in the rods and cones of the retina. Retinal is the fundamental structure involved in the transduction of light into visual signals, i.e. nerve impulses in the ocular system of the central nervous system.
Diagram of a human eye; note that not all eyes have the same anatomy as a human eye. The mammalian eye can also be divided into two main segments: the anterior segment and the posterior segment. [10] The human eye is not a plain sphere but is like two spheres combined, a smaller, more sharply curved one and a larger lesser curved sphere.
The posterior segment or posterior cavity [1] is the back two-thirds of the eye that includes the anterior hyaloid membrane and all of the optical structures behind it: the vitreous humor, retina, choroid, and optic nerve. [2]
The elements composing the layer of rods and cones (Jacob's membrane) in the retina of the eye are of two kinds, rod cells and cone cells, the former being much more numerous than the latter except in the macula lutea. Jacob's membrane is named after Irish ophthalmologist Arthur Jacob, who was the first to describe this nervous layer of the ...