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Related to sclera: conjunctiva, Blue 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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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.



The hard outer coat of the eye, continuous with the cornea in front and with the sheath of the optic nerve behind.


the firm white fibrous membrane that forms the outer covering of the eyeball
References in periodicals archive ?
The animals within each set were identical except for the eyes, which varied with respect to the size, colour and presence of sclera.
1, Typical dark spots on the sclera and a dark skin lesion and collected urine was black).
CUTLINE: Elizabeth Sclera, 7, holds the bucket she put out at her birthday party to collect donations for Beaman Memorial Library.
Redness of the sclera is believed to be a general but important sign of a person's emotional and biological state.
Neonatal jaundice refers to the discolouration of the skin and sclera resulting from an accumulation of bilirubin in the skin and mucosa.
Also included are chapters on the preparation and preservation of amniotic membrane to treat severe ocular surface diseases, the preparation and use of human sclera grafts in ophthalmic surgery, and culturing retinal pigment epithelium (RPE) cells for RPE banking.
They love it when they really look at their eyes and see all the parts--the pupil, iris, sclera, eyelid, eyelashes and the eyebrow.
The proposed criteria for focal choroidal invasion are defined as a tumor focus of less than 3 mm in any diameter (thickness or width) and not reaching the sclera (Figure 1, b).
As you may expect from the title the book explores the topic of iridology, however all aspects of this remarkable clinical tool are integrated from Australian, European and American teachings, including iris, sclera and pupil, emotional and constitutional aspects.
The diagnosis of MS was established on the characteristics of tall stature, intermaxillary narrowness, myopia, retinitis pigmentosa, blue sclera, scoliosis, pectus excavatum, arachnodactyly and diminished ratio of Us/Ls.
What happens is that the layer of tissue next to the sclera, the 'white' of the eye, becomes inflammed.
It is an inflammation of part or all of the uvea, the middle (vascular) tunic of the eye, although it also commonly involves the sclera, the cornea, and the retina.