The ophthalmic nerve is one of the three branches of the trigeminal nerve

Trigeminal nerve

The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...

, the fifth cranial nerve. The ophthalmic nerve carries only sensory fibers.

Branches

• Nasociliary nerve
  Nasociliary nerve
  The nasociliary nerve is a branch of the ophthalmic nerve. It is intermediate in size between the two other main branches of the ophthalmic nerve, the frontal nerve and the lacrimal nerve, and is more deeply placed.-Path:...
  
  
  • sensory root of ciliary ganglion
    Sensory root of ciliary ganglion
    Sensory fibers from the eyeball run posteriorly through the short ciliary nerves and pass through the ciliary ganglion without forming synapses...
    
    
  • posterior ethmoidal nerve
    Posterior ethmoidal nerve
    The posterior ethmoidal nerve is a branch of the nasociliary nerve.It passes through the posterior ethmoidal foramen, with the posterior ethmoidal artery.It carries sensory information from the sphenoid sinus and posterior ethmoidal air cells....
    
    
  • long ciliary nerve
  • infratrochlear nerve
    Infratrochlear nerve
    The infratrochlear nerve is given off from the nasociliary just before it enters the anterior ethmoidal foramen.It runs forward along the upper border of the medial rectus, and is joined, near the pulley of the superior oblique, by a filament from the supratrochlear nerve.It then passes to the...
    
    
  • anterior ethmoidal nerve
    Anterior ethmoidal nerve
    The anterior ethmoidal nerve is a nerve which provides sensory branches to the nasal cavity. The nerve is the continuation of the Nasociliary nerve after it enters the anterior ethmoidal foramen into the anterior ethmoidal air cells. The nasociliary nerve arises from the Ophthalmic division of...
    
    
• lacrimal nerve
  Lacrimal nerve
  The lacrimal nerve is the smallest of the three branches of the ophthalmic division of the trigeminal nerve.It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch that goes from the ophthalmic to the trochlear nerve.It passes forward in a separate...
  
  
• frontal nerve
  Frontal nerve
  The frontal nerve is the largest branch of the ophthalmic nerve, and may be regarded, both from its size and direction, as the continuation of the nerve....
  
  
  • supratrochlear nerve
    Supratrochlear nerve
    The supratrochlear nerve is a branch of the frontal nerve, which itself comes from the ophthalmic division of the trigeminal cranial nerve.It is smaller than the nearby supraorbital nerve...
    
    
  • supraorbital nerve
    Supraorbital nerve
    The supraorbital nerve is a terminal branch of the frontal nerve.It passes through the supraorbital foramen, and gives off, in this situation, palpebral filaments to the upper eyelid...
    
    

Path

The ophthalmic nerve supplies branches to the cornea

Cornea

The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

, ciliary body

Ciliary body

The ciliary body is the circumferential tissue inside the eye composed of the ciliary muscle and ciliary processes. It is triangular in horizontal section and is coated by a double layer, the ciliary epithelium. This epithelium produces the aqueous humor. The inner layer is transparent and covers...

, and iris

Iris (anatomy)

The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...

; to the lacrimal gland

Lacrimal gland

The lacrimal glands are paired almond-shaped glands, one for each eye, that secrete the aqueous layer of the tear film. They are situated in the upper, outer portion of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. Inflammation of the lacrimal glands is called...

 and conjunctiva

Conjunctiva

The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...

; to the part of the mucous membrane

Mucous membrane

The mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line cavities that are exposed to the external environment and internal organs...

 of the nasal cavity

Nasal cavity

The nasal cavity is a large air filled space above and behind the nose in the middle of the face.- Function :The nasal cavity conditions the air to be received by the other areas of the respiratory tract...

; and to the skin of the eyelids, eyebrow

Eyebrow

The eyebrow is an area of thick, delicate hairs above the eye that follows the shape of the lower margin of the brow ridges of some mammals. Their main function is to prevent sweat, water, and other debris from falling down into the eye socket, but they are also important to human communication and...

, forehead

Forehead

For the Arsenal striker see GervinhoIn human anatomy, the forehead is the fore part of the head. It is, formally, an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp...

 and nose

Human nose

The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consists mostly of cartilage and which separates the nostrils...

.

It is the smallest of the three divisions of the trigeminal, and arises from the upper part of the trigeminal ganglion

Trigeminal ganglion

The trigeminal ganglion is a sensory ganglion of the trigeminal nerve that occupies a cavity in the dura mater, covering the trigeminal impression near the apex of the petrous part of the temporal bone.-Relations:It is somewhat crescentic in shape, with its convexity...

 as a short, flattened band, about 2.5 cm. long, which passes forward along the lateral wall of the cavernous sinus, below the oculomotor and trochlear nerve

Trochlear nerve

The trochlear nerve is a motor nerve that innervates a single muscle: the superior oblique muscle of the eye....

s; just before entering the orbit, through the superior orbital fissure, it divides into three branches, lacrimal, frontal, and nasociliary.

The frontal branch passes through the orbit superiorly, then reenters the frontal bone briefly before exiting above the orbit through the supraorbital foramen

Supraorbital foramen

The supraorbital foramen is a bony elongated path located above the orbit and under the forehead. The supraorbital foramen lies directly under the eyebrow....

 and the supratrochlear notch to provide sensory innervation for the skin of the forehead and scalp. The lacrimal nerve

Lacrimal nerve

The lacrimal nerve is the smallest of the three branches of the ophthalmic division of the trigeminal nerve.It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch that goes from the ophthalmic to the trochlear nerve.It passes forward in a separate...

 passes through the orbit superiorly to innervate the lacrimal gland

Lacrimal gland

The lacrimal glands are paired almond-shaped glands, one for each eye, that secrete the aqueous layer of the tear film. They are situated in the upper, outer portion of each orbit, in the lacrimal fossa of the orbit formed by the frontal bone. Inflammation of the lacrimal glands is called...

. The nasociliary branch gives off several sensory branches to the orbit and then continues out through the anterior ethmoidal foramen

Anterior ethmoidal foramen

Lateral to either olfactory groove are the internal openings of the anterior and posterior ethmoidal foramina .The anterior ethmoidal foramen, situated about the middle of the lateral margin of the olfactory groove, transmits the anterior ethmoidal vessels and the anterior ethmoidal nerve; the...

, where it enters the nasal cavity and provides innervation for much of the anterior nasal mucosa. It also gives off a branch which exits through the nasal bones to form the external nasal branch.

The ophthalmic nerve is joined by filaments from the cavernous plexus

Cavernous plexus

The cavernous nerve plexus is situated below and medial to that part of the internal carotid artery which is placed by the side of the sella turcica in the cavernous sinus, and is formed chiefly by the medial division of the internal carotid nerve....

 of the sympathetic, and communicates with the oculomotor, trochlear, and abducent

Abducent nerve

The abducens nerve or abducent nerve is a somatic efferent nerve that controls the movement of a single muscle, the lateral rectus muscle of the eye, in humans. In most other mammals it also innervates the musculus retractor bulbi, which can retract the eye for protection...

 nerves; it gives off a recurrent (meningeal) filament which passes between the layers of the tentorium

Tentorium cerebelli

The tentorium cerebelli or cerebellar tentorium is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes.-Anatomy:...

.