September 01, 2018

Cornea problems

Beyond blurred vision

For the cornea to work properly, it must be transparent to allow light in and it must have a smooth, symmetric curve so that light rays come together at the same place on the retina. When the transparency, texture or shape of the cornea is altered, vision problems may result.

Cornea

The corneas of your eyes act much like windows, which allow sunlight to illuminate a dark room. These thin, clear structures serve a number of purposes, including protecting your eyes and starting the translation of light into vision. But if something goes wrong, blurry or impaired vision may result.

A critical and complex barrier

The cornea is the clear, dome-shaped structure that serves as your eye's outermost layer. The tissues of the cornea are arranged in three main layers. The outermost layer (epithelium) blocks the passage of foreign materials into the eye while allowing the absorption of oxygen and tears.

The middle layer (stroma) is the thickest layer of the cornea. It's made up mainly of water and collagen — a protein that gives the cornea strength and elasticity.

The innermost layer of the cornea (endothelium) keeps the cornea clear. Fluid from inside the eye normally leaks into the stroma, and the endothelium's task is to pump away excess fluid, to maintain a delicate balance.

For the cornea to work properly, it needs to maintain two properties. It must be transparent to allow light in, and it must have a smooth, symmetric curve so that all of the light rays come together at the same place on the retina. The cornea and the eye lens are critical to focusing your vision. When the transparency, texture or shape of the cornea is altered, vision problems may result.

Dryness and allergies

When you blink, tears are distributed across the cornea to keep...