Search results
Results from the WOW.Com Content Network
The stroma is a delicate interlacement of fibres. Some circle the circumference of the iris and the majority radiate toward the pupil. Blood vessels and nerves intersperse this mesh. In dark eyes, the stroma often contains pigment granules. Blue eyes and the eyes of albinos, however, lack pigment.
The iris consists of two layers: the front pigmented fibrovascular layer known as a stroma and, behind the stroma, pigmented epithelial cells.. The stroma is connected to a sphincter muscle (sphincter pupillae), which contracts the pupil in a circular motion, and a set of dilator muscles (dilator pupillae), which pull the iris radially to enlarge the pupil, pulling it in folds.
The anterior segment or anterior cavity [1] is the front third of the eye that includes the structures in front of the vitreous humour: the cornea, iris, ciliary body, and lens. [2] [3] Within the anterior segment are two fluid-filled spaces: the anterior chamber between the posterior surface of the cornea (i.e. the corneal endothelium) and the ...
The middle portion of the optic cup develops into the ciliary body and iris. [7] During the invagination of the optic cup, the ectoderm begins to thicken and form the lens placode, which eventually separates from the ectoderm to form the lens vesicle at the open end of the optic cup. [1] [3] [4]
This template is a navigation box relating to anatomy that provides links to related topics. When editing the links in this template: Include a single link to the article. Do not add: synonyms or information about the structure itself (eg nerve or muscle supply). These should be found within an article.
They are arranged in a circle, and form a sort of frill behind the iris, around the margin of the lens.. They vary from sixty to eighty in number, lie side by side, and may be divided into large and small; the former are about 2.5 mm. in length, and the latter, consisting of about one-third of the entire number, are situated in spaces between them, but without regular arrangement.
The irises of human eyes exhibit a wide spectrum of colours. Eye color is a polygenic phenotypic trait determined by two factors: the pigmentation of the eye's iris [1] [2] and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.
Iris Gonioscopy of the anterior chamber angle. Schwalbe's line is the anatomical line found on the interior surface of the eye's cornea, and delineates the outer limit of the corneal endothelium layer. Specifically, it represents the termination of Descemet's membrane. [1] In many cases it can be seen via gonioscopy. [2]