When your eyelids are open you are exposing your eyes to all kinds of environmental damage. Dust, debris, and even ultraviolet radiation from the sun can all have a harmful effect if they are able to access the parts of the eye essential for sight.
To reduce the risk associated with keeping our eyes open throughout the day evolution has provided a useful protective layer, the Conjunctiva. On top of its role as a protective barrier the conjunctiva is also important in the production of tears and the maintenance of homeostasis in the eyes.
In this module we'll first explore the healthy conjunctiva and its various layers and glands. Next we will turn to conjunctivitis which is the proper medical term for that nearly ubiquitous illness "pink eye." There are many different types of conjunctivitis so we will take special care to distinguish between the causes, appearance, and treatment of each.
Without our conjunctiva we'd be at constant risk of damaging our eyes during the simple act of looking at things. Let's take a deeper look at how this defender keeps our eyes in working condition.
The Sclera, like sclerosis and sclerotic, gets its name from Latin and Greek words meaning "hard." The sclera is the white of the eye, and if you press on your own sclera through your eyelid you will feel that it is quite firm. The eyes are usually thought of as delicate or squishy structures and while it is true that the eyes are important enough to demand protection these organs are able to maintain their own structure thanks to the sclera.
In this module we will look at the anatomy of the whites of the eye. We will consider what the sclera is made of at a microscopic level. And we will consider how changes at the small scale can manifest themselves in significant differences in the eye as a whole.
Finally, we will discuss several different types of scleral pathology, and we will learn how the sclera can be helpful in diagnosing some systemic diseases and genetic disorders.
When we glance at someone's eyes usually the colorful iris is the first thing we notice. But that iris only appears so colorful because of the white backdrop provided by the sclera.