sclera


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Related to sclera: conjunctiva, Blue Sclera

sclera:

see eyeeye,
organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of eye are the simple eye, found in many invertebrates, and the compound eye, found in insects and many other
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.

Sclera

 

the external tough fibrous tunic of the eye, which performs a supportive and protective function. In most vertebrates the sclera contains cartilaginous tissue and bony laminae that form a sclerotic ring. (Chondrichthians and modern amphibians and mammals do not have sclerotic rings.)

In humans the sclera consists of a dense fibrous tissue in which intermixed collagenous and elastic fibers are arranged predominantly in meridional and equatorial directions. Connective tissue cells are located between the fibers, and pigment cells (melanocytes) are found where the optic nerve leaves the eye. The external layer of the sclera contains a highly motile system of slender collagenous fibers and laminae separated from one another by slitlike cavities (Tenon’s capsule); the fibers and laminae facilitate rotation of the eyeball in various directions. The external surface of the sclera is attached to the tendons of the oculomotor muscles.

In humans the thickness of the sclera at the posterior pole of the eyeball is approximately 1 mm, at the equator approximately 0.3–0.4 mm, and at the anterior pole of the eyeball at the site of the transition into the cornea approximately 0.6 mm. Small branching cavities are found at the junction of the sclera and cornea; the cavities join to form Schlemm’s canal, which drains fluid from the anterior chamber of the eye.

O. G. STROEVA

sclera

[′skler·ə]
(anatomy)
The hard outer coat of the eye, continuous with the cornea in front and with the sheath of the optic nerve behind.

sclera

the firm white fibrous membrane that forms the outer covering of the eyeball
References in periodicals archive ?
The sclera is the outermost layer of the posterior part of the eye.
The eyes are a really interesting gateway into the body -- tears can tell you how much glucose you have, sclera can tell you how much bilirubin is in your blood," said senior author Shwetak Patel, the Washington Research Foundation Entrepreneurship Endowed Professor in Computer Science & Engineering and Electrical Engineering.
Effect of pterygium morphology on pterygium recurrence in a controlled trial comparing conjunctival autografting with bare sclera excision.
Acute scleral thinning after pterygium excision with intraoperative mitomycin C: a case report of scleral dellen after bare sclera technique and review of the literature.
The clear visibility of the sclera is a uniquely human characteristic.
The standard treatment for pterygium is surgical excision with bare sclera technique which is associated with recurrence as high as 24-89%.
The eye is depicted in a repeated rectangular format, even the sclera of the eye is in a rectangular format.
Halegoua-De Marzio, the patient's physical examination showed normal mental status, icteric sclera, mild abdominal distension and lower extremity edema.
The Slit Lamp facilitates an examination of the frontal structures and posterior segment of the human eye, including the eyelid, sclera, conjunctiva, iris, natural crystalline lens, and cornea.
At its circumference the cornea joins the white of the eye, called the sclera.
The company said that the active non-infectious anterior scleritis is the inflammation of the sclera, which is the fibrous white membrane surrounding the eyeball excluding the cornea.
The sclera covers the vitreous humor, a jelly-like material that fills the eyeball and is mostly water.