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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.
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 central retinal artery supplies blood to all the nerve fibers that form the optic nerve, which carries the visual information to the lateral geniculate nucleus of the thalamus, including those that reach over the fovea. Its blood flow can be revealed by fluorescein angiography or laser Doppler imaging. [4]
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.
Studies have shown that people can tell the difference in the letters of a word in the fovea and near-parafovea (the part of the parafovea closest to the fovea), but not in the outer edges of the parafovea. [3] In languages that read from left to right, the word immediately to the right of the fixated word is known as the parafoveal word. [3]
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 ...
It has two points at which it is different; the fovea and optic disc. The fovea is a dip in the retina directly opposite the lens, which is densely packed with cone cells. It is largely responsible for color vision in humans, and enables high acuity, such as is necessary in reading.
The main purpose of the bulbus oculi is to refract photons passing through the cornea, pupil, and lens to focus onto the retina, where the photons in the refracted light rays trigger electric and chemical reactions within the layers of the retina, specifically the fovea centralis. These reactions are then passed as electrical signals through ...