Fiber membrane (outer mold)

Vascular membrane (tunica media): On the inner surface of the outer membrane, it is rich in blood vessels and pigment cells and is brown-black in color.

Retina (intima): On the inner surface of the media, it can be divided into three parts from front to back: the iris part of the retina, the ciliary body part of the retina, and the choroidal part of the retina. The iris part of the retina and the ciliary body part are attached to the iris and ciliary body The inner surface of the retina has no photosensitive effect, so it is called the blind part of the retina. The choroidal part of the retina is the part of the optic organ that receives light wave stimulation and converts it into nerve impulses, so it is called the retinal optic part. The optic nerve begins with an oval The circular disc-shaped structure is called the optic disc, also known as the optic nerve head. The edge of the optic disc is raised, and the central retinal artery and vein pass through it. There are no photoreceptor cells, which is called a physiological blind spot. On the temporal side of the optic disc There is a small yellow area about 3.5mm slightly lower, called the macula, and its central depression is called the fovea. This area has no blood vessels and is the most sensitive part of the light sensitivity. It is composed of dense cone cells. The nerve layer of the optic part of the retina is mainly composed of three layers Composed of nerve cells, the outer layer is cones and rods, the middle layer is bipolar cells, and the inner layer is ganglion cells

Aqueous humor: A colorless, transparent liquid that fills the eye chamber. Aqueous humor is produced by the ciliary body, fills the posterior chamber of the eye, passes through the pupil to the anterior chamber, and finally enters the scleral venous sinus through the iridocorneal space, and joins the ophthalmic vein through the anterior ciliary vein.

Lens: Located between the iris and vitreous body, it is biconvex, elastic, and contains no blood vessels or nerves. The curvature of the lens changes with the distance of the object being viewed

Vitreous body: It is a colorless and transparent gel-like substance located between the lens, ciliary body and retina, supporting the retina.

Levator palpebrae superioris muscle: Contraction can lift the upper eyelid and open the eye fissure. It is innervated by the oculomotor nerve.

Superior rectus muscle: Located below the levator palpebrae superioris muscle and above the eyeball. Contraction turns the pupil upward and inward, innervated by the oculomotor nerve

Inferior rectus muscle: below the eyeball, contraction can turn the pupil downward and inward, innervated by the oculomotor nerve

Medial rectus muscle: Contraction can turn the pupil inward and is innervated by the oculomotor nerve

Lateral rectus: located on the outside of the eyeball. Contraction can turn the pupil to the outside. It is innervated by the abducens nerve.

Superior oblique muscle: Contraction can turn the pupil downward and outward, innervated by the trochlear nerve

Inferior oblique muscle: Contraction can turn the pupil upward and outward, innervated by the oculomotor nerve

Cochlea: located in front of the vestibule, shaped like a snail shell, composed of the modiolus and the modiolus.

Vestibule: is the middle part of the bony labyrinth. Its lateral wall is the medial wall of the tympanum, with vestibular window and cochlear window. The medial wall is the floor of the internal auditory canal, and the posterior wall has five openings of the bony semicircular canals.

Bony semicircular canals: They are three semi-circular bony canals, which are located in three mutually perpendicular planes and arranged at right angles to each other. They are the anterior bony semicircular canal, the outer bony semicircular canal and the posterior bony semicircular canal. Each bone semicircular canal has two bony feet, one is enlarged and is called the ampullae foot, and the other is small and is called the single bone foot. The single bony crura of the anterior and posterior semicircular canals are combined into a common bony crura