This article provides an overview of the major components of the eye, including the sclera, conjunctiva, cornea, iris, lens, choroid, vitreous, and retina. It explains the functions of each part, such as the sclera's role in eye movement, the cornea's refractive power, the iris's control of light entry through the pupil, and the retina's function in light detection. Understanding these basic anatomical features is essential for grasping the pathophysiology of eye conditions.
This is the white part of the eye, visible to the naked eye. It is formed of opaque tissue and is attached to extraocular muscles which control the movement of the eye.
Diagram showing the cornea and sclera of the eye.
A thin layer of transparent connective tissue covers the front part of the sclera and folds back on itself into the inside part of the eyelids. This layer of connective tissue is known as the conjunctiva.
The dome-shaped transparent part of the eye is called the cornea. The cornea provides most of the refractive power of the eye through which light beams are focused.
The tears which line the surface of the cornea provide a medium for oxygen exchange, since the cornea itself is avascular.
The cornea has five layers:
Each of these five layers of the cornea have separate functions, however, we will not be covering those in this basic anatomy article.
Diagram showing the five layers of the cornea.
Through the cornea, we can see the coloured part of the eye, called the iris. The iris forms an aperture through which light beams can travel into the eye, known as the pupil.
Diagram of the various structures of the eye.
The iris also contains muscles that control the size of the pupil. The iris will constrict the pupil upon exposure to bright light and will dilate in exposure to darkness.