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Introduction to Corneal Disorders

By

Melvin I. Roat

, MD, FACS, Sidney Kimmel Medical College at Thomas Jefferson University

Last full review/revision May 2020| Content last modified May 2020
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The cornea is the clear layer in front of the iris and pupil. It protects the iris and lens and helps focus light on the retina. It is composed of cells, protein, and fluid. The cornea looks fragile but is almost as stiff as a fingernail. However, it is very sensitive to touch.

An Inside Look at the Eye

An Inside Look at the Eye

Corneal disorders include the following:

Corneal disease or damage can cause pain, tearing, and decreased sharpness of vision (visual acuity).

A slit lamp Slit-Lamp Examination A person who has eye symptoms should be checked by a doctor. However, some eye disorders cause few or no symptoms in their early stages, so the eyes should be checked regularly (every 1 to 2... read more , which is an instrument that enables a doctor to examine the eye under high magnification, is usually used to examine the cornea. During the examination, the doctor may apply eye drops that contain a yellow-green dye called fluorescein. The fluorescein temporarily stains damaged areas of the cornea, making it possible to see damaged areas that are not otherwise visible.

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Test your knowledge

Herpes Zoster Ophthalmicus
Herpes zoster ophthalmicus is an infection of the eye caused by the varicella-zoster virus. This virus also causes chicken pox and shingles. Which of the following describes the mechanism by which herpes zoster ophthalmicus causes infection?
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