Eye Anatomy
Learn about the structures of the human eye and how they work together to provide clear, comfortable vision. Understanding eye anatomy is the foundation for recognizing common eye diseases and maintaining lifelong eye health.
Understanding the Human Eye
The structures below are organized from the front (anterior) to the back (posterior) of the eye to help illustrate the path of light and the relationship between the major ocular structures.
Figure 1. Cross-sectional anatomy of the human eye illustrating the major ocular structures discussed below.
Cornea
The transparent front surface that provides most of the eye’s focusing power.
Conjunctiva
A thin membrane covering the white of the eye and inner eyelids.
Tear Film
A thin layer of tears that lubricates, nourishes, and protects the surface of the eye.
Meibomian Glands
Specialized oil-producing glands within the eyelids that secrete meibum to reduce tear evaporation and maintain a healthy tear film.
Eyelids
Protect the eyes from injury, spread tears during blinking, and help keep the eyes moist.
Lacrimal Gland
Produces tears that lubricate, nourish, and protect the surface of the eye.
Iris
The colored part of the eye that regulates the amount of light entering the eye.
Pupil
The opening in the iris through which light enters.
Lens
A clear structure that changes shape to focus light onto the retina.
Zonules (Suspensory Ligaments)
Tiny fibers that suspend the lens and allow it to change shape during focusing.
Ciliary Body
Produces aqueous humor and controls lens focusing.
Aqueous Humor
Fluid that nourishes the front of the eye and helps maintain normal eye pressure.
Trabecular Meshwork
The drainage tissue that helps regulate intraocular pressure.
Schlemm’s Canal
Collects aqueous humor after it leaves the trabecular meshwork.
Vitreous Humor
Clear gel filling the back of the eye and helping maintain its shape.
Retina
Light-sensitive tissue that converts light into nerve signals.
Ora Serrata
The junction between the retina and the ciliary body, marking the anterior limit of the retina.
Macula
The center of the retina responsible for sharp central vision.
Fovea
The area of highest visual acuity located within the macula.
Choroid
A vascular layer supplying oxygen and nutrients to the retina.
Optic Disc
The point where the optic nerve exits the eye, creating the natural blind spot.
Optic Nerve
Carries visual information from the eye to the brain.
Extraocular Muscles
Six muscles surrounding the eye that control eye movements and maintain proper alignment.
Sclera
The strong white outer coat that protects the eye and provides attachment for the extraocular muscles.
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