Collier's sign

Collier's sign (also known as Collier's tucked lid sign or posterior fossa stare ) is bilateral or unilateral eyelid retraction. It is an accepted medical sign of a midbrain lesion, first described in 1927 by J Collier. With the eyes in the primary position, the sclera can be seen above the cornea, and further upgaze increases the distance between the eyelids and irises. Causes include upper dorsal midbrain supranuclear lesions such as Parinaud's syndrome, 'top of the basilar syndrome', midbrain infarction, neurodegeneration or tumour, multiple sclerosis, encephalitis, and Miller-Fisher syndrome.

Progressive supranuclear palsy

supranuclear palsysupranuclear palsy, progressiveProgressive Supranuclear Ophthalmoplegia
Some of the other signs are poor eyelid function, contracture of the facial muscles, a backward tilt of the head with stiffening of the neck muscles, sleep disruption, urinary incontinence, and constipation. The visual symptoms are of particular importance in the diagnosis of this disorder. Patients typically complain of difficulty reading due to the inability to look down well. Notably, the ophthalmoparesis experienced by these patients mainly concerns voluntary eye movement and the inability to make vertical saccades, which is often worse with downward saccades. Patients tend to have difficulty looking down (a downgaze palsy) followed by the addition of an upgaze palsy.

Oculomotor nerve

oculomotorIIIcranial nerve III
It enters the orbit via the superior orbital fissure and innervates extrinsic eye muscles that enable most movements of the eye and that raise the eyelid. The nerve also contains fibers that innervate the intrinsic eye muscles that enable pupillary constriction and accommodation (ability to focus on near objects as in reading). The oculomotor nerve is derived from the basal plate of the embryonic midbrain. Cranial nerves IV and VI also participate in control of eye movement. The oculomotor nerve originates from the third nerve nucleus at the level of the superior colliculus in the midbrain.


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.


blinkBlinksBlinking reflex
The Müller’s muscle, or the superior tarsal muscle, in the upper eyelid and the inferior palpebral muscle in the lower 3 eyelid are responsible for widening the eyes. These muscles are not only imperative in blinking, but they are also important in many other functions such as squinting and winking. The inferior palpebral muscle is coordinated with the inferior rectus to pull down the lower lid when one looks down. Though one may think that the stimulus triggering blinking is dry or irritated eyes, it is most likely that it is controlled by a "blinking center" of the globus pallidus of the lenticular nucleus—a body of nerve cells between the base and outer surface of the brain.

Levator palpebrae superioris muscle

levator palpebrae superiorislevator palpebraeLevator palpebræ superioris
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.

Nictitating membrane

third eyelidnictating membranehaw
The nictitating membrane is a transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining vision. The term comes from the Latin word nictare, meaning "to blink". It is often called a third eyelid or haw, and may be referred to in scientific terminology as the plica semilunaris, membrana nictitans, or palpebra tertia. Unlike the upper and lower eyelids, the nictitating membrane moves horizontally across the eyeball. In many species, any stimulus to the eyeball (such as a puff of air) will result in reflex nictitating membrane response.

Orbicularis oculi muscle

orbicularis oculiorbicularisorbicularis muscle
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.


conjunctivalbulbar conjunctivaconjunctival sac
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.

Tarsus (eyelids)

tarsal plateSuperior tarsustarsi
The lateral angles are attached to the zygomatic bone by the lateral palpebral raphe. The medial angles of the two plates end at the lacrimal lake, and are attached to the frontal process of the maxilla by the medial palpebral ligament). The sulcus subtarsalis is a groove in the inner surface of each eyelid.

Meibomian gland

meibomian glandstarsal glandsmeibomian gland dysfunction
Meibomian glands (often written with a small "m" and also called tarsal glands) are holocrine type exocrine glands, along the rims of the eyelid inside the tarsal plate. They produce meibum, an oily substance that prevents evaporation of the eye's tear film. Meibum prevents tears spilling onto the cheek, trapping the tears between the oiled edge and the eyeball, and making the closed lids airtight. There are about 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. The glands are named after Heinrich Meibom (1638–1700), a German physician.

Orbital 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.


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. A chalazion is 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.

Supraorbital nerve

supraorbitalSupra-orbital nervesuperior orbital nerve
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.

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.


ChalaziaChalazion cysteyelid cysts
Painless swelling on the eyelid. Eyelid tenderness typically none to mild. Increased tearing. Heaviness of the eyelid. Redness of conjunctiva. Sebaceous gland adenoma. Sebaceous gland carcinoma. Sarcoid granuloma. Foreign body granuloma.


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.

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).

Sebaceous gland

sebumsebaceous glandssebaceous
Meibomian glands, in the eyelids, secrete a form of sebum called meibum onto the eye, that slows the evaporation of tears. It also serves to create an airtight seal when the eyes are closed and its lipid quality also prevents the eyelids from sticking together. The meibomian glands are also known as tarsal glands, Zeis glands and palpebral glands. They attach directly to the follicles of the eyelashes, which are arranged vertically within the tarsal plates of the eyelids. Fordyce spots, or Fordyce granules, are ectopic sebaceous glands found on the genitals and oral mucosa. They show themselves as yellowish-white milia (milk spots).

Lateral palpebral arteries

lateral palpebral branches
The lateral palpebral arteries are small arteries which supply the eyelid. * Medial palpebral arteries


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

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.

Henri Parinaud

He is well known for the medical term Parinaud's syndrome, which is, "a dorsal midbrain lesion such as pinealoma which results in vertical gaze palsy, convergence-retraction nystagmus and light-near dissociation". Another medical condition named after him is Parinaud's oculoglandular syndrome (fever, papillar conjunctivitis and lymphadenopathy), a rare manifestation of cat scratch disease (caused by the bacteria Bartonella), which he was first to describe. Cat scratch fever. A Clinical Lesson at the Salpêtrière.


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.