How does the sclera work in the eye?

Answer 1

The sclera is the opaque white fibrous tissue of the eyeball itself. This fibrous tissue extends across the front of the eye, except where the cornea and iris are located in the center front of the eye, and it extends around to back of the eye where it meets the blood vessels and optic nerve.

Answer 2

The Sclera is the posterior opaque white/off-white surface of the eye; this dense fibrous tissue envelops the entire posterior surface of the eye, excluding the continuous anteriorly of the cornea, iris, and pupil which is at its center. The visible covering extends outward from the cornea as it wraps around the eye-bulb to the external sheath of the optic nerve and where the nerve exits (lamina cribrosa). It is the eye's thickest tissue and it vary in depth; in general, at its thickest it is about 1mm at the front of the eye, and it thins as it moves toward the back of the eye. The sclera can be a color other than white/off-white; the color and its shade can vary from light to dark, in yellows, blues, and red. The color variation can be due to age, inherited disorder, illness, disease, tissue thinning or irritation.

The sclera's function is to protect the exterior and intraocular content of the eye, block-out/refract light, maintain the shape of the eye-bulb, and provide an area for extraocular tendons and muscles to attach. A transparent mucous membrane covers the anterior of the sclera, cornea, and conjunctiva; it supplies mucosal moisture that lubricates, cleanses debris and allergens from the eye, as it helps protect the sclera, cornea and conjunctiva. Its cellular make-up is that of molecular proteins, collagen, pigment cells, and photosensitive cells. The sclera is made of connective tissues; some of these tissues are the episcera (an outer layer of tissue between the stoma and the conjunctiva); lamina fusca (a thin inner layer that contains pigment cells); and cartilaginous layer (a flexible cartilage behind the eye's lens, which provides some stiffness and reinforces the sclera); scleral stroma (the thick tissue of the mid-eye); conjunctiva (a transparent covering that covers the sclera); and fatty pads (orbital fat that surrounds and protects nerve fibers, it is not a tissue, but it is important to eye health and stability).

Answer 3

The sclera is an outer fibrous layer that encases and protects the eyeball.

The cornea controls and focuses the entry of light into the eye, protects against germs and other matter from entering the eye as well.

Answer 4

Definition

The sclera is the white outer wall of the eye. It is a tough, fibrous tissue that extends from the cornea (the clear front section of the eye) to the optic nerve at the back of the eye. The sclera gives the eye its white color.

Answer 5

Definition

The sclera is the white outer wall of the eye. It is a tough, fibrous tissue that extends from the cornea (the clear front section of the eye) to the optic nerve at the back of the eye. The sclera gives the eye its white color.

Reviewed By

Review Date: 08/14/2011

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

Answer 6

the sclera is the white part of eye