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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 fovea centralis is a small, central pit composed of closely packed cones in the eye.It is located in the center of the macula lutea of the retina. [1] [2]The fovea is responsible for sharp central vision (also called foveal vision), which is necessary in humans for activities for which visual detail is of primary importance, such as reading and driving.
Photograph of the retina of the human eye, with overlay diagrams showing the positions and sizes of the macula, fovea, and optic disc. Perifovea is a region in the retina that circumscribes the parafovea and fovea and is a part of the macula lutea. [1] The perifovea is a belt that covers a 10° radius around the fovea and is 1.5 mm wide.
The macula corresponds to the central 17 degrees diameter of the visual field; the fovea to the central 5.2 degrees, and the foveola to 1–1.2 degrees diameter. [10] [11] [12] Note that in the clinical literature the fovea can refer to the central 1–1.2 deg, i.e. what is otherwise known as the foveola, and can be referred to as the "clinical ...
Thus if the central retinal artery gets occluded, there is complete loss of vision in that eye even though the fovea is not affected. The entire retina (with the exception of the fovea) becomes pale and swollen and opaque while the central fovea still appears reddish (this is because the choroid color shows through).
The foveal avascular zone (FAZ) is a region within the fovea centralis at the centre of the retina of the human eye that is devoid of retinal blood vessels. The geometric centre of the FAZ is often taken to be the centre of the macula and thus the point of fixation.
Parafovea or the parafoveal belt is a region in the retina that circumscribes the fovea and is part of the macula lutea. [1] It is circumscribed by the perifovea.. Photograph of the retina of the human eye, with overlay diagrams showing the positions and sizes of the macula, fovea, and optic disc
Illustration of the distribution of cone cells in the fovea of an individual with normal color vision (left), and a color blind (protanopic) retina. Note that the center of the fovea holds very few blue-sensitive cones. Distribution of rods and cones along a line passing through the fovea and the blind spot of a human eye [7]