Macula of retina

As a yellow spot ( macula lutea in Latin ) of the area of the human retina is called the highest density of photoreceptor cells. It is in the center of the retina ( retinal ) temporal ( temple sides ) of the optic disc and has a diameter between about 2.5 and 5.0 mm.

The color of the yellow spot is barely visible during life and is caused by embedded in the retina pigments ( lutein and zeaxanthin ). The macula lutea was first described by Samuel Thomas von Soemmerring as " yellow spot ".

Looking at the back of the eye not to be confused with the yellow spot is the much more conspicuous, pink -colored optic disc, also called a blind spot where the optic nerve, the central artery and central vein enter and exit the eye. Here there are no photoreceptor cells. The color of the optic disc comes through the translucence of the white sclera about through the blood-carrying capillaries of the nerve tissue.

Design and function

The photoreceptor cells of the yellow spot are mainly responsible for the color vision cones.

  • The sharpest vision ( fine spatial resolution ) will be held in the fovea centralis, a component of the yellow spot which contains only cones (diameter about 0.5 mm). In relation to the entire retina, the ratio of cones to rods only 1:20 ( 6 million cones, 120 million rods ).
  • In the subsequent 0.5 mm wide zone ( the parafovea ) rods are increasingly available.
  • The outermost 1.5 mm wide area of the macula, the region of highest density of rods and is referred to as Perifovea.

By the eye movement constantly changing portions of the environment can be projected onto the fovea. The impression of a sharp overall image is produced in the retina subsequent instances of the brain.

Diseases

Fundus (eye) Blind spot (vision) Capillary (disambiguation)
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