All Topics  
Eyelid

 
Eyelid

 
   Email Print
   Bookmark   Link
 

 

Eyelid
 
 
  Topics Eyelid Topic Home

An eyelid is a thin fold of skin that covers and protects an eye
Eye

Eyes are Organ that detect light, and send signals along the optic nerve to the visual system and other areas of the brain. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system....
. With the exception of the prepuce
Prepuce

The prepuce is a retractable piece of skin which covers part of the genitals of primates and other mammals.* On a male, this covers the head of the penis ....
 and the labia minora
Labia minora

The labia minora or nymphae are two Longitudinal#Anatomy cutaneous folds on the human vulva. They are situated between the labia majora, and extend from the clitoris obliquely downward, laterally, and backward on either side of the vulval vestibule, ending between bottom of the vulval vestibule and the labia majora....
, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle
Levator palpebrae superioris muscle

The levator palpebrae superioris is the muscle in the orbit that elevates the superior eyelid....
 retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily. The human eyelid features a row of eyelash
Eyelash

An eyelash or simply lash is one of the hairs that grow at the edge of the eyelid. Eyelashes protect the eye from debris and perform some of the same function as vibrissae do on a cat or a mouse in the sense that they are sensitive to being touched, thus providing a warning that an object is near the eye ....
es which serve to heighten the protection of the eye from dust and foreign debris. "Palpebral" (and "blepharo") means relating to the eyelids.

he human eyelid, there are various layers; from superficial to deep, they are: skin
Skin

The skin is the outer covering of the body, also known as the epidermis. It is the largest organ of the integumentary system made up of multiple layers of epithelial biological tissue, and guards the underlying muscles, bones, ligaments and organ s....
, subcutaneous tissue
Subcutis

The subcutaneous tissue is a layer of fat that lies between the dermis of the skin and underlying fascia. Subcutaneous fat insulates the body, absorbs trauma, and is a reserve energy source....
, orbicularis oculi
Orbicularis oculi muscle

The 'orbicularis oculi' is a muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and borders of a short fibrous band, the medial palpebral ligament....
, orbital septum
Orbital septum

The orbital septum is a membranous sheet that acts as the anterior boundary of the Orbit . It extends from the orbital rims to the eyelids.In the upper eyelid it blends with the tendon of the Levator palpebr? superioris, and in the lower eyelid with the Tarsus ....
 & tarsal plates, and palpebral conjunctiva
Conjunctiva

The conjunctiva is a clear mucous membrane consisting of cells and underlying basement membrane that covers the sclera and lines the inside of the eyelids....
.






Discussion
Ask a question about 'Eyelid'
Start a new discussion about 'Eyelid'
Answer questions from other users
Full Discussion Forum



Encyclopedia


An eyelid is a thin fold of skin that covers and protects an eye
Eye

Eyes are Organ that detect light, and send signals along the optic nerve to the visual system and other areas of the brain. Complex optical systems with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system....
. With the exception of the prepuce
Prepuce

The prepuce is a retractable piece of skin which covers part of the genitals of primates and other mammals.* On a male, this covers the head of the penis ....
 and the labia minora
Labia minora

The labia minora or nymphae are two Longitudinal#Anatomy cutaneous folds on the human vulva. They are situated between the labia majora, and extend from the clitoris obliquely downward, laterally, and backward on either side of the vulval vestibule, ending between bottom of the vulval vestibule and the labia majora....
, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle
Levator palpebrae superioris muscle

The levator palpebrae superioris is the muscle in the orbit that elevates the superior eyelid....
 retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily. The human eyelid features a row of eyelash
Eyelash

An eyelash or simply lash is one of the hairs that grow at the edge of the eyelid. Eyelashes protect the eye from debris and perform some of the same function as vibrissae do on a cat or a mouse in the sense that they are sensitive to being touched, thus providing a warning that an object is near the eye ....
es which serve to heighten the protection of the eye from dust and foreign debris. "Palpebral" (and "blepharo") means relating to the eyelids.

Anatomy


Layers

In the human eyelid, there are various layers; from superficial to deep, they are: skin
Skin

The skin is the outer covering of the body, also known as the epidermis. It is the largest organ of the integumentary system made up of multiple layers of epithelial biological tissue, and guards the underlying muscles, bones, ligaments and organ s....
, subcutaneous tissue
Subcutis

The subcutaneous tissue is a layer of fat that lies between the dermis of the skin and underlying fascia. Subcutaneous fat insulates the body, absorbs trauma, and is a reserve energy source....
, orbicularis oculi
Orbicularis oculi muscle

The 'orbicularis oculi' is a muscle in the face that closes the eyelids. It arises from the nasal part of the frontal bone, from the frontal process of the maxilla in front of the lacrimal groove, and from the anterior surface and borders of a short fibrous band, the medial palpebral ligament....
, orbital septum
Orbital septum

The orbital septum is a membranous sheet that acts as the anterior boundary of the Orbit . It extends from the orbital rims to the eyelids.In the upper eyelid it blends with the tendon of the Levator palpebr? superioris, and in the lower eyelid with the Tarsus ....
 & tarsal plates, and palpebral conjunctiva
Conjunctiva

The conjunctiva is a clear mucous membrane consisting of cells and underlying basement membrane that covers the sclera and lines the inside of the eyelids....
. The meibomian glands lie within the eyelid and secrete the lipid part of the tearfilm
Tears

Tears are the liquid product of a process of lacrimation to clean and lubricate the eyes. The word lacrimation may also be used in a medical or literary sense to refer to crying....
.

Skin
The skin is similar to areas elsewhere, but have more pigment cells. In diseased persons these may wander and cause a discoloration of the lids. It contains sweat glands and hairs, the latter becoming eyelashes as the border of the eyelid is met.

Innervation

In humans, the sensory nerve supply to the upper eyelids is from the infratrochlear, supratrochlear, supraorbital
Supraorbital

Supraorbital refers to the region immediately above the eye sockets, where in humans the eyebrows are located. It denotes several anatomical features, such as:...
 and the lacrimal nerve
Lacrimal nerve

The lacrimal nerve is the smallest of the three branches of the ophthalmic nerve.It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve....
s from the ophthalmic branch (V1) of the trigeminal nerve
Trigeminal nerve

The trigeminal nerve is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system....
 (CN V). The skin of the lower eyelid is supplied by branches of the infratrochlear at the medial angle, the rest is supplied by branches of the infraorbital nerve
Infraorbital nerve

After the maxillary nerve enters the infraorbital canal, the nerve is frequently called the infraorbital nerve. This nerve innervates the lower eyelid, upper lip, and part of the vestibule and exits the infraorbital foramen of the maxilla....
 of the maxillary branch (V2) of the trigeminal nerve.

Blood supply

In humans, the eyelids are supplied by two arches on each upper and lower lid. The arches are formed by anastamoses of the lateral palpebral arteries
Lateral palpebral arteries

The lateral palpebral arteries are small arteries which supply the eyelid.See also* Medial palpebral arteries...
 and medial palpebral arteries
Medial palpebral arteries

The medial palpebral arteries are arteries of the head. They are two in number, superior and inferior, arise from the ophthalmic, opposite the pulley of the Obliquus superior....
, branching off from the lacrimal artery
Lacrimal artery

The lacrimal artery arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery: not infrequently it is given off before the artery enters the Orbit ....
 and ophthalmic artery
Ophthalmic artery

The ophthalmic artery is a branch of the internal carotid artery which supplies branches to supply the eye and other structures in the orbit . It enters the orbit together with the Optic nerve through the Optic canal....
, respectively.


Death

After death
Death

Death is the permanent termination of the biological functions that define a life organism. It refers to both a particular event and to the condition that results thereby....
, it is common in many cultures to pull the eyelids of the deceased down to close the eyes. This is a typical part of the last offices
Last offices

The last offices are the procedures performed, usually by a nurse in the developed world, to a dead person shortly after death has been confirmed....
.

See also


Disorders

Stye02
*Blepharospasm
Blepharospasm

A blepharospasm , is any abnormal tic or twitch of the eyelid.It normally refers to benign essential blepharospasm, a focal dystonia - a neurological movement disorder involving involuntary and sustained muscle contractions of the muscles around the eyes....
  • Cellulitis
    Cellulitis

    Cellulitis is a diffuse infection of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin Flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters, burn , insect bites, surgical wounds, or sites o...
  • Chalazion
    Chalazion

    A chalazion , also known as a meibomian gland lipogranuloma, is a cyst in the eyelid that is caused by inflammation of a blocked meibomian gland, usually on the upper eyelid....
  • Dermatochalasis
    Dermatochalasis

    Dermatochalasis is a medical condition. It is defined as an excess of skin in the upper or lower eyelid. It may be either an acquired or a congenital condition. It is generally treated with blepharoplasty....
  • Ectropion
    Ectropion

    Ectropion is a medical condition in which the lower eyelid turns outwards. It is one of the notable aspects of newborns exhibiting Harlequin type ichthyosis....
  • Entropion
    Entropion

    Entropion is a medical condition in which the eyelids fold inward. It is very uncomfortable, as the eyelashes rub against the cornea constantly....
  • Hay-Wells syndrome
    Hay-Wells syndrome

    Hay-Wells syndrome is one of at least 150 known types of ectodermal dysplasia.These disorders affect tissue that arise from the ectodermal germ layer, such as skin, hair, and nails....
  • Ptosis
    Ptosis (eyelid)

    Ptosis is an abnormally low position of the upper eyelid. The drooping may be worse after being awake longer, when the individual's muscles are tired....
  • Stye (Hordeolum)
    Stye

    A stye or hordeolum is an infection of the sebaceous glands at the base of the eyelashes. Styes are similar to chalazion, but tend to be of smaller size and feel much more painful and usually produce no lasting damage....


Surgeries

  • Asian blepharoplasty
    Asian blepharoplasty

    Asian blepharoplasty, also known as "double eyelid surgery," is a type of cosmetic surgery where the skin around the eye is reshaped . The purpose of the procedure is to create an upper eyelid with a crease from an eyelid without a crease ....
  • Blepharoplasty
    Blepharoplasty

    Blepharoplasty can be both a functional and cosmetic surgical procedure intended to reshape the upper eyelid or lower eyelid by the removal or repositioning of excess tissue as well as by reinforcement of surrounding muscles and tendons....
  • Epicanthoplasty
    Epicanthoplasty

    Epicanthoplasty sometimes referred to as "Westernization" is a type of eye surgery to remove the presence of epicanthal folds. It is considered to be a challenging procedure by some surgeons because the epicanthal folds overlay the lacrimal canaliculi ....


Additional images