Umbo (eye) on:
[Wikipedia]
[Google]
[Amazon]
The foveola is located within a region called the 
Material was copied from this source, which is available under
Creative Commons Attribution 4.0 International License
Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were prepared from 32 foveolae from monkeys (''Macaca fascicularis'') and humans. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. It was discovered that in monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 μm in diameter) of humans and monkeys.
File:Macula lutea.svg, Schematic diagram of the macula lutea of the retina, showing perifovea, parafovea, fovea, and clinical macula
File:Retina-OCT800.png, Time-Domain OCT of the macular area of a retina at 800 nm, axial resolution 3 µm
File:SD-OCT Macula Cross-Section.png, Spectral-Domain OCT macula cross-section scan.
File:Macula Histology OCT.jpg, alt=macula histology (OCT), macula histology (OCT)
File:Retinography.jpg, A
macula
The macula (/ˈmakjʊlə/) 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 and is subdivided into the umbo, foveola, foveal av ...
, a yellowish, cone photoreceptor filled portion of the human retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...
. Approximately 0.35 mm in diameter, the foveola lies in the center of the fovea
Fovea () (Latin for "pit"; plural foveae ) is a term in anatomy. It refers to a pit or depression in a structure.
Human anatomy
*Fovea centralis of the retina
* Fovea buccalis or Dimple
* Fovea of the femoral head
* Trochlear fovea of the fr ...
and contains only cone cells and a cone-shaped zone of Müller cells. In this region the cone receptors are found to be longer, slimmer, and more densely packed than anywhere else in the retina, thus allowing that region to have the potential to have the highest visual acuity in the eye.
The center of the foveola is sometimes referred to as the umbo, a small (150-200µm) center of the floor of the foveola; features elongated cones. The umbo is the observed point corresponding to the normal light reflex but not solely responsible for this light reflex.
The anatomy of the foveola was recently reinvestigated. Material was copied from this source, which is available under Creative Commons Attribution 4.0 International License
Serial semithin and ultrathin sections, and focused ion beam (FIB) tomography were prepared from 32 foveolae from monkeys (''Macaca fascicularis'') and humans. Serial sections and FIB analysis were then used to construct 3D models of central Müller and photoreceptor cells. It was discovered that in monkeys, outer segments of central foveolar cones are twice as long as those from parafoveal cones and do not run completely parallel to the incident light. Unique Müller cells are present in the central foveolae (area of 200 μm in diameter) of humans and monkeys.
Additional images
fundus photograph
Fundus photography involves photographing the rear of an eye, also known as the fundus. Specialized fundus cameras consisting of an intricate microscope attached to a flash enabled camera are used in fundus photography. The main structures that ...
showing the macula as a spot to the left. The optic disc is the area on the right where blood vessels converge. The grey, more diffuse spot in the centre is a shadow artifact.
Notes
Human eye anatomy Visual system {{eye-stub