Eyelash

eyelashesciliaryeyelashes,
Blepharitis is the irritation of the lid margin, where eyelashes join the eyelid. The eyelids are red and itching, the skin often becomes flaky, and the eyelashes may fall out. Distichiasis is the abnormal growth of lashes from certain areas of the eyelid. Trichiasis refers to ingrown eyelashes. Eyelashes may become infested with parasitic crab louse. An external hordeolum, or stye, is a purulent inflammation of infected eyelash follicles and surrounding sebaceous (Gland of Zeis) and apocrine (Moll's gland) glands of the lid margin. Trichotillomania is a disorder that urges the sufferer to pull out scalp hair, eyelashes, etc.

Orbicularis oculi muscle

orbicularis oculiorbicularis musclemuscle of Riolan
In addition, the orbital and palpebral portions can work independent of each other, as in the furrowing of the brows by contraction of the orbital to reduce glare while keeping the eyes open by virtue of the relaxation of the palpebral. Each time the eyelids are closed through the action of the orbicularis, the medial palpebral ligament is tightened, the wall of the lacrimal sac is thus drawn lateralward and forward, so that a vacuum is made in it and the tears are sucked along the lacrimal canals into it.

Levator palpebrae superioris muscle

levator palpebrae superiorislevator palpebraelevator
The levator palpebrae superioris (Latin for: elevating muscle of upper eyelid) is the muscle in the orbit that elevates the superior (upper) eyelid. The levator palpebrae superioris originates on the lesser wing of the sphenoid bone, just above the optic foramen. It broadens and decreases in thickness (becomes thinner) and becomes the levator aponeurosis. This portion inserts on the skin of the upper eyelid, as well as the superior tarsal plate. It is a skeletal muscle. The superior tarsal muscle, a smooth muscle, is attached to the levator palpebrae superioris, and inserts on the superior tarsal plate as well.

Conjunctiva

conjunctivalconjuctivabulbar conjunctiva
The conjunctiva is a tissue that lines the inside of the eyelids and covers the sclera (the white of the eye). It is composed of unkeratinized, stratified squamous epithelium with goblet cells, and stratified columnar epithelium. The conjunctiva is highly vascularised, with many microvessels easily accessible for imaging studies. The conjunctiva is typically divided into three parts: Blood to the bulbar conjunctiva is primarily derived from the ophthalmic artery. The blood supply to the palpebral conjunctiva (the eyelid) is derived from the external carotid artery.

Meibomian gland

meibomian glandsmeibomian gland dysfunctiontarsal glands
The Meibomian gland (often written with a small "m" and also called tarsal gland) is a holocrine type of exocrine gland, at the rim of the eyelid inside the tarsal plate, responsible for the supply of meibum, an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tear spillage onto the cheek, trapping tears between the oiled edge and the eyeball, and makes the closed lids airtight. There are approximately 50 glands on the upper eyelid and 25 glands on the lower eyelid. Dysfunctional meibomian glands often cause dry eyes, one of the more common eye conditions. They may also contribute to blepharitis.

Orbital septum

septum
The orbital septum (Palpebral fascia) is a membranous sheet that acts as the anterior boundary of the orbit. It extends from the orbital rims to the eyelids. It forms the fibrous portion of the eyelids. In the upper eyelid, the orbital septum blends with the tendon of the levator palpebrae superioris, and in the lower eyelid with the tarsal plate. When the eyes are closed, the whole orbital opening is covered by the septum and tarsi. Medially it is thin, and, becoming separated from the medial palpebral ligament, attaches to the lacrimal bone at its posterior crest.

Supraorbital nerve

supraorbitalsuperior orbital nervesupra-orbital
It passes through the supraorbital foramen, and gives off, in this situation, palpebral filaments to the upper eyelid. Additionally it supplies the conjunctiva of the eye, the frontal sinus and the skin from the forehead extending back to the middle of the scalp.

Stye

hordeolumstyesexternal hordeolum
A stye, also known as a hordeolum, is a bacterial infection of an oil gland in the eyelid. This results in a red tender bump at the edge of the eyelid. The outside or the inside of the eyelid can be affected. The cause of a stye is usually a bacterial infection by Staphylococcus aureus. The internal ones are due to infection of the meibomian gland while the external ones are due to an infection of the gland of Zeis. A chalazion on the other hand is a blocked oil gland without infection. They are typically in the middle of the eyelid and not painful. Often a stye will go away without any specific treatment in a few days or weeks. Recommendations to speed improvement include warm compresses.

Infraorbital nerve

infra-orbital nerveinfraorbital portion
This nerve innervates (sensory) the lower eyelid, upper lip, and part of the nasal vestibule and exits the infraorbital foramen of the maxilla. There is a cross innervation of this nerve on the other side of jaw. The infraorbital nerve block is a type of local anesthetic nerve block used to induce analgesia in the distribution of the nerve for whatever purpose. After a fracture of the floor of the orbit, the infraorbital nerve may become trapped, producing an area of anaesthesia under the orbital rim. Infraorbital artery. External nasal nerve. Internal nasal branches of infraorbital nerve.

Gland of Zeis

glands of ZeisZeiszeis gland
Glands of Zeis are unilobar sebaceous glands located on the margin of the eyelid. The glands of Zeis service the eyelash. These glands produce an oily substance that is issued through the excretory ducts of the sebaceous lobule into the middle portion of the hair follicle. In the same area of the eyelid, near the base of the eyelashes are apocrine glands called the "glands of Moll". If eyelashes are not kept clean, conditions such as folliculitis may take place, and if the sebaceous gland becomes infected, it can lead to abscesses and styes. The glands of Zeis are named after German ophthalmologist Eduard Zeis (1807–68). * List of specialized glands within the human integumentary system

Ophthalmic artery

ophthalmicartery to the eyeLateral muscular branch
The OA continues anteriorly to the trochlea where the medial palpebral arteries (superior and inferior) arise and supply the eyelids. The OA terminates in two branches, the supratrochlear (or frontal) artery and the dorsal nasal artery. Both exit the orbit medially to supply the forehead and scalp. Because of the obvious importance of the ocular globe, branches of the ophthalmic artery often are subdivided into two groups: those that supply the eyeball (ocular group) and those that supply non-ocular orbital structures (orbital group).

Blepharitis

blephartiseyelidsgranulation of the eyelids
Swollen eyelids - due to inflammation. Crusting at the eyelid margins/base of the eyelashes/medial canthus, generally worse on waking - due to excessive bacterial buildup along the lid margins. Eyelid sticking - due to crusting along the eyelid margin. Eyelid itching - due to the irritation from inflammation and epidermis scaling of the eyelid. Flaking of skin on eyelids - due to tear film suppressed by clogged meibomian glands. Gritty/burning sensation in the eye, or foreign-body sensation - due to crusting from bacteria and clogged oil glands. Frequent blinking - due to impaired tear film from clogged oil glands unable to keep tears from evaporating. Light sensitivity/photophobia.

Entropion

in-turnedinward rolling of lower eyelidsinward-folded eyelid
Entropion is a medical condition in which the eyelid (usually the lower lid) folds inward. It is very uncomfortable, as the eyelashes continuously rub against the cornea causing irritation. Entropion is usually caused by genetic factors. This is different from when an extra fold of skin on the lower eyelid causes lashes to turn in towards the eye (epiblepharon). In epiblepharons, the eyelid margin itself is in the correct position, but the extra fold of skin causes the lashes to be misdirected. Entropion can also create secondary pain of the eye (leading to self trauma, scarring of the eyelid, or nerve damage). The upper or lower eyelid can be involved, and one or both eyes may be affected.

Lacrimal artery

lacrimal
Its terminal branches, escaping from the gland, are distributed to the eyelids and conjunctiva: of those supplying the eyelids, two are of considerable size and are named the lateral palpebral arteries; they run medially in the upper and lower lids respectively and anastomose with the medial palpebral arteries, forming an arterial circle in this situation. The lacrimal artery also give off one or two zygomatic branches, one of which passes through the zygomatico-temporal foramen, to reach the temporal fossa, and anastomoses with the deep temporal arteries; another appears on the cheek through the zygomatico-facial foramen, and anastomoses with the transverse facial.

Ectropion

Ectropion is a medical condition in which the lower eyelid turns outwards. It is one of the notable aspects of newborns exhibiting congenital Harlequin-type ichthyosis, but ectropion can occur due to any weakening of tissue of the lower eyelid. The condition can be repaired surgically. Ectropion is also found in dogs as a genetic disorder in certain breeds. Ectropion in dogs usually involves the lower eyelid. Often the condition has no symptoms, but tearing and conjunctivitis may be seen. Breeds associated with ectropion include the Cocker Spaniel, the Saint Bernard, the Bloodhound, the Clumber Spaniel, and the Basset Hound. It can also result from trauma or nerve damage.

Blepharochalasis

Blepharochalasis is an inflammation of the eyelid that is characterized by exacerbations and remissions of eyelid edema, which results in a stretching and subsequent atrophy of the eyelid tissue, leading to the formation of redundant folds over the lid margins. It typically affects only the upper eyelids, and may be unilateral as well as bilateral. Complications of blepharochalasis may include conjunctival hyperemia (excessive blood flow through the moist tissues of the orbit), chemosis, entropion, ectropion, and ptosis. Blepharochalasis is idiopathic in most cases, i.e., the cause is unknown.

Blepharospasm

benign essential blepharospasmblepharospasmodic contractionseyelid
Blepharospasm is any abnormal contraction or twitch of the eyelid. The condition should be distinguished from the more common, and milder, involuntary quivering of an eyelid, known as myokymia. In most cases, blepharospasm symptoms last for a few days and then disappear without treatment, but in some cases the twitching is chronic and persistent, causing life-long challenges. In these cases, the symptoms are often severe enough to result in functional blindness. The person's eyelids feel like they are clamping shut and will not open without great effort. People have normal eyes, but for periods of time are effectively blind due to their inability to open their eyelids.

Ptosis (eyelid)

ptosisblepharoptosisdrooping eyelid
Ptosis due to trauma can ensue after an eyelid laceration with transection of the upper eyelid elevators or disruption of the neural input. Other causes of ptosis include eyelid neoplasms, neurofibromas or the cicatrization after inflammation or surgery. Mild ptosis may occur with aging. A drooping eyelid can be one of the first signals of a third nerve palsy due to a cerebral aneurysm, that otherwise is asymptomatic and referred to as an oculomotor nerve palsy. Use of high doses of opioid drugs such as morphine, oxycodone, heroin, or hydrocodone can cause ptosis. Pregabalin, an anticonvulsant drug, has also been known to cause mild ptosis.

Blepharoplasty

eyelid surgeryblepharoplastieseye lift
Sequentially, lower eyelid blepharoplasty can successfully address the anatomic matters of excess eyelid skin, slackness of the eye-muscles and of the orbital septum (palpebral ligament), excess orbital fat, malposition of the lower eyelid, and prominence of the nasojugal groove, where the orbit (eye socket) meets the slope of the nose.