Conjunctiva
and Lisa Vogel, medical editorEva Rudolf-Müller is a freelance writer in the medical team. She studied human medicine and newspaper sciences and has repeatedly worked in both areas - as a doctor in the clinic, as a reviewer, and as a medical journalist for various specialist journals. She is currently working in online journalism, where a wide range of medicine is offered to everyone.
More about the expertsLisa Vogel studied departmental journalism with a focus on medicine and biosciences at Ansbach University and deepened her journalistic knowledge in the master's degree in multimedia information and communication. This was followed by a traineeship in the editorial team. Since September 2020 she has been writing as a freelance journalist for
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The conjunctiva (conjunctiva) is a type of mucous membrane that covers the inside of the eyelids and connects them to the eyeball. It extends from the edge of the eyelid to the cornea. The conjunctiva is well supplied with blood and very sensitive to external stimuli. Read everything you need to know about the conjunctiva!
What is the conjunctiva
The conjunctiva (conjunctiva) is a mucous membrane-like layer of tissue that connects the eyeball (Bulbus oculi) with the eyelids. It is well supplied with blood, transparent, moist, smooth and shiny. The conjunctiva is firmly fused in the area of the eyelid. It rests a little looser on the eyeball. The conjunctiva covers the dermis (sclera) up to the edge of the cornea. There is no conjunctiva in the area of the cornea that covers the iris and pupil, otherwise the cornea would be cloudy.
The conjunctiva is very sensitive to external stimuli.
The three sections of the conjunctiva
The conjunctiva (conjunctiva) consists of three sections:
- Lid conjunctiva: It covers the inside of the eyelids. Medical term: conjunctiva tarsi or tunica conjunctiva palpebrarum.
- Conjunctiva: It covers the front, visible part of the eyeball. Medical term: conjunctiva bulbi or tunica conjunctiva bulbi.
- Upper and lower conjunctival sac: These two folds form the transition between the eyelid and the conjunctiva. The medical term for the conjunctival sac is Saccus conjunctivalis.
The structure of the conjunctiva
The conjunctiva consists of several layers of cells. In this non-keratinized squamous epithelium, sporadic mucus-forming goblet cells and additional lacrimal glands are embedded. The secretion of the conjunctiva is used to moisten the eye and is an important part of the tear film.
Underneath, separated by a basement membrane, there is a layer of loose connective tissue (lamina propria; subconjunctiva). It is criss-crossed by many fine blood vessels.
The conjunctival blood vessels are usually invisible. If the eye is irritated, they will be filled with more blood (conjunctival injection) - the eye will turn red.
The conjunctiva is firmly and immovably connected to the eyelid cartilage (tarsus palpebrae), a crescent-shaped, flexible plate of connective tissue in the upper and lower eyelids, which gives the lids a little firmness.
In the area of the inner corner of the eye a small, curved fold of the mucous membrane (Plica semilunaris conjunctivae). This is a rudimentary remnant of the well-mobile nictitating membrane still preserved in animals, which is also known as the "third eyelid".
The conjunctiva is easy to move in the area of the white dermis. In the area of the edge of the cornea, it is firmly attached to the subsurface again and merges into the epithelium of the cornea.
On the back surface of the eyelids, the conjunctiva has follicles with plasma cells and lymphocytes, which represent a barrier for pathogens and are involved in the immune response.
Sensitive and resorbable
Because the conjunctiva is heavily pervaded by sensitive nerves, it reacts accordingly sensitively to stimuli, foreign bodies or the like. In addition, it is very absorbent, which is why many drugs for the eyes are instilled into the conjunctival sac.
What problems can the conjunctiva cause?
Various complaints and diseases can occur in the conjunctival area.
acid burns
Accidents involving strong acids, alkalis or other chemicals can cause burns to the conjunctiva and cornea. In the worst case, the affected eye loses its vision.
Rapid action is necessary in the event of burns to the eyes! Always alert the emergency services in the event of accidents involving chemicals.
Inflammation of the conjunctiva
Conjunctivitis (conjunctivitis) can be recognized by a "red" eye, a foreign body sensation in the eye and a watery, slimy or even purulent secretion. The possible triggers of inflammation are many:
Pathogens (such as bacteria, viruses, fungi) are often the cause of conjunctivitis.
In other cases, the inflammation is the result of an allergy: For example, a so-called rhinoconjunctivitis can develop in the context of house dust allergy, animal hair allergy or hay fever. This is a combination of an inflammation of the lining of the nose (with a runny or blocked nose) and an inflammation of the conjunctiva.
Very often, however, conjunctivitis is also triggered by unspecific stimuli. These include, for example:
- smoke
- dust
- heat
- cold
- wind
- UV light
- Eye strain, e.g. due to long work at the PC, exhaustion, lack of sleep or incorrectly correcting glasses
- Misalignment of the eyelids: ectropion (turning an eyelid outward) and entropion (turning an eyelid inward)
- Trichiasis: Inward turning of the eyelashes without entropion - the eyelashes rub against the conjunctiva, which can become inflamed
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