|
Horizontal Eccentricity
Horizontal eccentricity refers to the horizontal axis, measured in degrees, along the visual field. The blind spot extends from an eccentricity ''d''1 to eccentricity ''d''2 in temporal direction from the fovea. The size of the blind spot can be calculated as :\arctan \left(\frac\right) - \arctan \left(\frac\right). External links Blind Spot {{eye-stub Eye Vision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temple (anatomy)
The temple is a latch where four skull bones fuse: the frontal, parietal, temporal, and sphenoid. It is located on the side of the head behind the eye between the forehead and the ear. The temporal muscle covers this area and is used during mastication. Cladists classify land vertebrates based on the presence of an upper hole, a lower hole, both, or neither in the cover of dermal bone that formerly covered the temporalis muscle, whose origin is the temple and whose insertion is the jaw. The brain has a lobe called the temporal lobe. Etymology The word "templar" as used in anatomy has a separate etymology from the other meaning of word ''temple'', meaning "place of worship". Both come from Latin, but the word for the place of worship comes from ', whereas the word for the part of the head comes from Vulgar Latin *', modified from ', plural form ("both temples") of ', a word that meant both "time" and the part of the head. Due to the common source with the word for time, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fovea Centralis
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. 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 fovea is surrounded by the ''parafovea'' belt and the ''perifovea'' outer region. The parafovea is the intermediate belt, where the ganglion cell layer is composed of more than five layers of cells, as well as the highest density of cones; the perifovea is the outermost region where the ganglion cell layer contains two to four layers of cells, and is where visual acuity is below the optimum. The perifovea contains an even more diminished density of cones, having 12 per 100 micrometres versus 50 per 100 micrometres in the most central fovea. That, in turn, is surrounded by a larger peripheral area, which delivers highly compres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
