Ocular Anatomy Quiz

Study Notes

The eye is a spherical organ located in the orbital cavity, measuring approximately 2.5 cm in diameter.
The space between the eye and the orbital cavity is filled with fatty tissue, providing cushioning and protection.
The eye's structure comprises three layers:
- Outer fibrous layer: Sclera and cornea
- Middle vascular layer: Iris, ciliary body, and choroid
- Inner nervous tissue layer: Retina
Key internal structures of the eyeball:
- Aqueous humor
- Lens
- Vitreous
Accessory structures supporting the eye:
- Eyebrows
- Eyelids and eyelashes
- Lacrimal apparatus
- Extraocular muscles
- Conjunctiva
- Orbital fat

The sclera, commonly known as the white of the eye, forms the outermost layer providing structural support.
It measures around 1 mm in thickness and thins at the optic nerve entry point, forming the Lamina cribrosa.
The cornea, the transparent, ellipsoid front portion of the eye, is the primary refractive surface.
It contributes a dioptric power of +43 ± 1.
The juncture between the cornea and sclera is referred to as the limbus, containing a small network of blood vessels.

The iris, the colored part of the eye, is a circular diaphragm with a central opening - the pupil.
It divides the anterior segment of the eye into anterior and posterior chambers, both filled with aqueous humor.
The ciliary body, triangular in shape, is responsible for producing aqueous humor and controlling lens shape.
It is attached to the iris and comprises pars plicata and pars plana.
The choroid, a dark brown, highly vascular layer, lies between the sclera and retina.
It extends from the ora serrata to the optic nerve opening in the sclera.

The retina, composed of ten layers of nerve cells and fibers, lines about 3/4 of the eyeball.
It contains a yellow area called macula lutea with a central depression known as the fovea centralis - the most sensitive area of the retina.

A clear fluid secreted by the ciliary epithelium, it fills both the anterior and posterior chambers, passing through the pupil from the posterior to the anterior chamber and subsequently draining through the canal of Schlemm.

This transparent, circular, biconvex structure sits behind the pupil, suspended by suspensory ligaments (zonule of Zinn) from the ciliary body.
It is encased within a transparent capsule.

This clear, colorless, inert gel occupies the posterior 4/5 of the eyeball.
It mostly consists of water (99%), with some salts and mucoprotein.
It contains a minimal number of cells, including hyalocytes and wandering leukocytes.