Conjunctivitis – Causes, Symptoms & Treatment


Conjunctivitis , or conjunctivitis , is inflammation of the conjunctiva in the eye. Especially the very red eyes are a typical sign of conjunctivitis. The causes are varied and range from bacterial inflammation to allergic reactions. Viruses can also lead to conjunctivitis of the eye through infection.

What is conjunctivitis?

Conjunctivitis, or conjunctivitis, is inflammation of the conjunctiva of the eye. The conjunctiva itself covers the outer shell of the eyeball as well as the inner side of the eyelids. This transparent mucous membrane produces the moist liquid mucus that the eye needs, which adheres to the eye as a tear film. The sense is less friction when moving and closing the eyes.

The conjunctiva is a thin, delicate, and transparent mucous membrane that lines the inside of the upper and lower lids and the front half of the eyeball, ending at the edge of the cornea midway between the lids. While it is firmly attached to the underlying tissue on the inside of the eyelids, it lies loosely on the eyeball.

The conjunctiva forms sac-shaped cavities, also called conjunctival sacs, when it moves from the inside of the eyelids to the eyeball. Eye drops and eye ointments can be easily introduced into the lower conjunctival sac for treatment if the lower eyelid is pulled down with your fingers and turned outwards.

In the case of inflammation, the conjunctiva, which is transparent when there is no inflammation and makes the eyeball appear white with the exception of the cornea, is supplied with much more blood. It then takes on a red color and becomes opaque, so that the underlying white sclera can no longer shimmer through and the eyeball appears pathologically red.

The conjunctiva is also responsible for the immune defense of the eye, so that the cornea and eyelids can also become inflamed in the case of conjunctivitis. Since the eyes and the conjunctiva are stored relatively unprotected in the body, they are often susceptible to external germs and stimuli.

Seen in this way, it is hardly surprising that conjunctivitis is one of the most common diseases of the eye. Typical are above all the strongly pronounced red eyes in conjunctivitis.


Conjunctivitis can have a variety of causes. In most cases, conjunctivitis is caused by viruses, fungi, parasites (e.g. worms ) or bacteria and is therefore an infectious disease . However, allergies and environmental irritants can also be triggers for conjunctivitis. These are primarily drafts, injuries, smoke, dust and substances.

In rare cases, conjunctivitis also occurs as part of another eye disease. Age-related eye disorders are also a cause. In the case of allergic causes, conjunctivitis can vary regionally and temporally, depending on the occurrence of allergens or pathogens.

As already mentioned, both external damage and internal diseases can be considered as the cause. External injuries include, for example, harmful effects of dust, smoke, foreign objects, chemical fumes, glare, poor or insufficient lighting conditions, drafts, irritation due to strong rubbing of the eyes, etc. Heavy smokers and people who are forced to be in the company of so-called Stopping chain smokers can also contract conjunctivitis.

Since conjunctivitis quite often tends to become chronic, it is necessary to eliminate external harmful influences. Most external damage often leads to conjunctivitis, especially when there is already a certain susceptibility of the conjunctiva.

Such a vulnerability can be caused, for example, by a slight refractive error in the eyes, which the patient is not aware of because it causes only a slight visual impairment. If the right glasses or contact lenses are prescribed in these cases, the disease can be cured very quickly. The same applies to normal-sighted people after the age of 45, in whom so-called presbyopia sets in.

Many of them fail to wear glasses for close-up work, or use glasses whose lenses have already become too weak, thereby unknowingly contributing to chronic conjunctivitis. When reading and writing, it is important to ensure that the field of vision is well lit, which is best achieved with an adjustable floor lamp. However, the light must not dazzle.

In many cases, conjunctivitis is also caused by pathogens (bacteria). If it is a question of very malignant bacteria, such as toxic pus pathogens, diphtheria bacilli, gonorrhea germs, etc., a violent inflammatory process can spread from the conjunctiva to the cornea, which melts, so to speak, and penetrates into the interior of the eyeball. Such severe inflammatory processes can only be stopped and the eyes saved through intensive specialist treatment.

In the case of newborn children of sexually transmitted mothers, preventive measures are taken to prevent them from developing such an inflammation, which in previous decades usually led to blindness. It is not uncommon for general infectious diseases , such as measles , typhus , etc., to go hand in hand with conjunctivitis. In all these cases, the pathogens must be identified with the help of microscopic examinations of the conjunctival secretion in order to be able to carry out targeted treatment.

Finally, conjunctivitis can also be caused by numerous substances and agents with which the patient comes into contact and to which he is hypersensitive or allergic. These include primarily flour dust and other types of dust, e.g. flower dust and pollen, which can cause hay fever and conjunctivitis, cosmetics, oil fumes, petrol, chemicals, etc., the latter of which very often get into the conjunctiva through rubbing the eyes while working.

Hypersensitivity and allergies to certain foods, such as strawberries, tomatoes, etc., can also cause conjunctivitis. Severe colds are also often associated with this disease. In addition, the tear ducts can be blocked, which can also result in persistent annoying tears and conjunctivitis.

Symptoms, Ailments & Signs

Conjunctivitis is manifested by various symptoms. The first sign is the redness of the eye. Due to the increased blood flow to the conjunctival vessels, there is a visible, mostly bright red discoloration at the edge of the iris. If deeper layers are inflamed, the edge of the iris appears bluish to reddish.

Accompanying the redness , the tear duct secretes purulent or mucous secretions, which often causes the eye to stick together. If an allergic reaction is the cause, the conjunctiva can swell. These so-called papillae are accompanied by a strong foreign body sensation.

In the case of severe inflammation, spasmodic eyelid closure can also occur. Allergic conjunctivitis is expressed by itching, sudden tears and accompanying symptoms such as a runny nose and sneezing . Bacterial conjunctivitis can also lead to purulent accumulations in the corners of the eyes. The viral form usually occurs on both sides and is characterized by swollen eyes and severe itching.

Depending on the degree of inflammation, the eye waters to a greater or lesser extent and secretes mucus and purulent secretions mainly at night, which often causes the lids to stick together completely, so that they can only be opened with great difficulty in the morning.

In severe cases, the eye can no longer be closed – the conjunctiva appears swollen and glassy. Viral or bacterial conjunctivitis can cause small bulges inside the eyelids. In addition, there is sensitivity to light and an annoying burning sensation , itching and a certain foreign body sensation, as if there were sand in the eyes.

All these phenomena are particularly pronounced in acute conjunctivitis . In chronic conjunctivitis , on the other hand, they are only slightly developed. Sometimes reddening of the conjunctiva can only be seen on the inside of the eyelids, while the conjunctiva of the eyeball looks completely normal.

Accordingly, the symptoms of chronic conjunctivitis are less pronounced and generally only occur with activities that strain the eyes, for example reading, writing and watching TV plus a computer, and also with smoking or in rooms where people smoke colder weather, wind and bright sunshine.


Untreated conjunctivitis is usually mild. The body’s self-healing process rarely leads to serious consequences for the eye and lifelong impairment of vision. Only sometimes can there be a loss of visual acuity if the cornea of ​​the eye has been injured or inflamed.

However, if pain occurs or other complications arise, a doctor should be consulted immediately.


Complications are more common with viral conjunctivitis than bacterial because it takes longer to heal and symptoms are more severe. A possible late consequence of conjunctivitis caused by viruses is clouding of the cornea . This visual disturbance can vary in severity and, with greatly reduced transparency, can have a significant impact on vision.

The formation of scars , particularly observable in infection with Chlamydia, near the lacrimal glands and ducts also impairs the lubrication of the eye. Chlamydia infections are also often chronic and make it necessary to also treat the partner of the person affected. Depending on the state of the immune system and the type of pathogen, bacterial inflammation can also have consequences that can lead to blindness.

The cornea can become inflamed, as can the bags under the eyes. They are located in the inner corner of the eyelid. Complications such as middle ear infections or meningitis are also possible. In any case, it is advisable to carry out any treatment with eye drops or antibiotics prescribed by the doctor until the end of the prescribed days. Even if the symptoms improve, premature termination can lead to renewed inflammation of the conjunctiva.

When should you go to the doctor?

If the eyes are red and burn or itch in certain situations, for example after long periods of screen work or when staying in very heated rooms, this is not yet a cause for concern. A doctor does not have to be consulted under these conditions. As a rule, a walk in the fresh air is enough for the eyes to recover. However, there are a number of situations in which burning or reddened eyes should be presented to the doctor immediately.

Conjunctivitis caused by pathogens such as bacteria, viruses or fungi are usually highly contagious. If your child comes home from daycare or school with red or irritated eyes, it is very likely that they have conjunctivitis. In this case, a doctor’s visit is strongly recommended. If the suspicion is confirmed, the school administration should be informed.

The doctor must also be consulted whenever changes in the eye occur after a trip abroad to tropical regions. In this case, the affected person could have been infected with a dangerous parasite. Herpes infections that spread to the eye can be particularly unpleasant and dangerous. In these cases, a doctor must be consulted immediately to prevent serious complications, including loss of vision.

Treatment & Therapy

The treatment or therapy of conjunctivitis depends on its specific cause. The severity and course of the disease are also important in the treatment. A distinction is therefore made between the treatment based on bacterial and viral causes as well as on external stimuli and allergic conjunctivitis.

According to the numerous causes, there is a whole range of treatment regulations. In general, the general practitioner or ophthalmologist initially prescribes mild disinfecting and anti-inflammatory eye drops and eye ointments, because this will already cure the majority of patients. In many cases, however, it is necessary to try several or a whole range of remedies.

Since it is only possible to determine more serious causes through repeated ophthalmological examinations, it is particularly advisable for those suffering from chronic conjunctivitis to visit the ophthalmologist again and again even if the medication prescribed so far has not helped. In addition, however, everyone affected should try to eliminate the damaging influences, whether at work or at home.

In the case of conjunctivitis caused by bacteria, no further treatment is usually necessary, as it heals on its own. However, the doctor may prescribe antibiotic eye drops or ointments to help. Antibiotics should only be used in severe cases. These can then be administered as tablets or eye drops.

There is no direct treatment for viral conjunctivitis. Only manually administered tear fluid and cold compresses can relieve the symptoms. The same procedure also applies to conjunctivitis caused by external stimuli, such as a draft.

If the cause is allergic, the allergy-causing substances, such as pollen, should be avoided. Here, too, cold compresses and artificial tears help against the acute symptoms. For a lasting improvement, antihistamines or mast cell stabilizers are prescribed by the doctor. As with all forms of allergies , hyposensitization to the causative allergens is a good idea.

Outlook & Forecast

Depending on the cause of the disorder and personal circumstances, the course and prognosis of conjunctivitis can vary greatly.

Simple bacterial inflammations of the conjunctiva are almost always successfully treated with eye drops containing antibiotics after the pathogen has been identified. The symptoms usually disappear completely within a few days. The prerequisite for this, however, is that the patient also strictly follows the treatment instructions of his doctor.

In particular, the eye drops should not be discontinued arbitrarily once the symptoms have disappeared. As a rule, the treatment must be carried out over a longer period of time in order to completely cure the inflammation and to avoid a recurrence. A new outbreak of the infection often results in a more severe course, and conjunctivitis can also become chronic.

Conjunctivitis caused by viruses is more difficult to treat, and recovery can often take weeks. During this time, symptoms such as severely reddened, watery or painful eyes can occur again and again. Normally, however, viral infections also heal without long-term consequences.

In exceptional cases, especially in people with a severely compromised immune system, it can also lead to very severe and persistent courses, whereby blindness due to conjunctivitis cannot be completely ruled out. However, this complication now occurs almost exclusively in patients in the developing world.


Conjunctivitis is a disease that can flare up again and again after it has subsided. Consistent aftercare is recommended to protect the eyes and avoid discomfort in advance. This can be done by the patient himself or by an ophthalmologist. In uncomplicated cases, the experienced family doctor can also examine the eyes for the condition of the conjunctiva. If necessary, he advises you to visit your family doctor again.

Aftercare primarily includes protecting the sensitive conjunctiva of the eye from further irritation. When washing your face, you should avoid using harsh cleaning agents, especially those with a high alcohol content. In addition, it is best to refrain from making up your eyes for a while to avoid particles of kajal, mascara or eye shadow getting into your eyes.

If you sweat a lot during sport, you can wear a headband to prevent drops of sweat from running into your eyes. Pollen allergy sufferers who have developed conjunctivitis through contact with pollen should avoid the allergens as much as possible during aftercare. If the conjunctivitis is caused by sun exposure, for example in the high mountains, the sunglasses are a valuable companion in aftercare. Drugs that the ophthalmologist has prescribed for local use can also be used after consultation after consultation. The same applies to eye moisturizers.

You can do that yourself

The medical treatment of conjunctivitis can be supported by various home remedies and self-help tips. One of the most important measures is increased hygiene . On the one hand, this prevents the inflammation from spreading to the other eye and to other people. On the other hand, lukewarm water reduces the oppressive feeling of foreign bodies and quickly flushes out pathogens. Alternatively, an eye bath, in which the eye is dipped in a glass of water, can also help.

In the event of severe inflammation, it is advisable to wear protective goggles . In general, contact with irritants such as wind, chlorinated water, smoke or extreme cold or heat should be avoided. Antiseptics (e.g. bibrocathol, povidone and zinc sulphate) from the pharmacy have an anti-inflammatory effect and help in the first few days of an inflammation.

In the further course, painful eye rims can also be dabbed with a little black tea. Other proven home remedies are, for example , eyebright , garden rue , marigold ointment or quark wraps. Tip: use woolen towels or disposable handkerchiefs to dry your eyes, which are thrown away after use.

If the inflammation spreads anyway or has not subsided after a week at the latest, another visit to the ophthalmologist is recommended .

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.