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[[Image:AcuityHumanEye.svg|270px |thumb |left| The diagram shows the relative acuity of the left human eye (horizontal section) in degrees from the fovea.<ref>Hans-Werner Hunziker, (2006) Im Auge des Lesers: foveale und periphere Wahrnehmung - vom Buchstabieren zur Lesefreude [ The function of the fovea is to catch detailed visual information 3 to 4 times per second at different parts of the [[visual field]]. The brain integrates this information within the framework of the condensed [[peripheral vision]] (extra-foveal information).
the eye of the reader: foveal and peripheral perception - from letter recognition to the joy of reading] Transmedia Stäubli Verlag Zürich 2006 ISBN 978-3-7266-0068-6</ref> ]]
In the human fovea the ratio of [[ganglion cell]]s to [[Photoreceptor cell|photoreceptor]]s is close to one; almost every photoreceptor has one ganglion cell receiving data from it. That is why it has little loss of sensory data, thus it is the area of the eye where most details can be seen.<ref>Smithsonian/The National Academies, ''Light:Student Guide and Source Book.'' [[Carolina Biological Supply Company]], 2002. ISBN 0-89278-892-5.</ref>▼
The human fovea has a diameter of about 1.0 mm with a high concentration of [[Cone cell|cone photoreceptor]]s. The center of the fovea is the foveola–about 0.2 mm in diameter–where only cone photoreceptors are present and there are virtually no [[rod cell|rods]].<ref name=WebvisionRetina/> The central fovea consists of very compact cones, thinner and more rod-like in appearance than cones elsewhere. Starting at the outskirts of the fovea, however, rods gradually appear, and the absolute density of cone receptors progressively decreases.
▲In the
Compared to the rest of the [[retina]], the cones in the foveal pit have a smaller diameter and can therefore be more densely packed (in a [[hexagon]]al pattern). The high spatial density of cones accounts for the high visual acuity capability at the fovea. This is enhanced by the local absence of retinal blood vessels from the fovea, which, if present, would interfere with the passage of [[light]] striking the foveal cone mosaic. The absence of inner retinal cells from the foveae of primates is assumed to contribute further to the high acuity function of the fovea.
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