Why do black people have bloodshot eyes

Red eye warning sign


The conjunctiva (conjunctiva) is a transparent, well-perfused, movable membrane that covers the eyeball. The conjunctiva consists of a multitude of cells that are involved in the production of parts of the tear film or the local immune defense. Inflammation of the conjunctiva is called conjunctivitis. This occurs either alone or in connection with inflammation of the eyelid margins (blepharoconjunctivitis) or the cornea (keratoconjunctivitis). It is characterized by reddening of the conjunctiva, often accompanied by symptoms such as oozing, burning and itching of the eyes. The visual acuity is usually maintained, a slightly blurred visual impression is sometimes described by the patient.

There are many causes of conjunctivitis. A distinction is made between non-infectious causes (keratoconjunctivitis sicca / blepharoconjunctivitis, allergic conjunctivitis) and infectious causes (viral / bacterial conjunctivitis). Important information about the genesis of conjunctivitis can be provided by the specific symptoms, the duration of the illness and the therapies that have been carried out to date.

Keratoconjunctivitis sicca

One of the most common causes of reddened conjunctiva is inflammation of the conjunctiva caused by dryness of the eyes called keratoconjunctivitis sicca. The eye depends on sufficient moisture. The tear film is made up of watery and greasy parts. The watery parts are produced by the lacrimal glands, the fatty part by glands, which are located in the area of ​​the lid edges. If the composition of the tear film is disturbed, it can cause irritation and even serious inflammatory conditions on the surface of the eye. Depending on the severity of the disease, the patient's symptoms range from a retrobulbar pressure sensation, an intermittent blurred visual impression, a feeling of tiredness / tension in the eyes through burning, itching, increased tearing of the eyes (epiphora) to marked deterioration in vision and severe pain. However, patients with a severe expression of dry eyes are usually already undergoing permanent ophthalmological treatment.

Therapeutic measures initially include tear substitutes, with preservative-free preparations being preferred. The market offers a wide range of tear substitutes. Advice on product selection should include the characteristics of the symptoms, possible allergies and the handling of the dosing containers. At the latest when the use of artificial tears does not improve the symptoms, a visit to an ophthalmologist should be recommended. This can determine the severity of the disease and derive an adequate therapy from this. In addition to tear substitutes, this can also include, for. B. include topical steroids or local immunomodulation. Chronic eyelid inflammation can also be the cause of the symptoms (see blepharitis).

In addition to drug therapy, the ophthalmologist can also take non-drug therapy measures. For example, ametropia should be corrected, as this can also be the cause of dry eye discomfort. Occlusion of the tear points is also a therapeutic option. Misalignments of the eyelids can also lead to moisture problems in the eye and may have to be corrected surgically.

In addition, systemic diseases can manifest themselves through impaired moisture in the eyes. Cooperation between the ophthalmologist and doctors from other specialties may therefore be indicated for diagnosis and treatment decisions.

Infectious conjunctivitis

The classic symptoms of conjunctivitis are itching in the area of ​​the eyes, increased secretion of secretions (tears, pus) and marked reddening of the eyes, sometimes with swelling of the conjunctiva. Many viral conjunctivitis occur as a side effect in the context of a general infection, e.g. B. a cold or a flu. Symptomatic therapy with tear substitutes is often sufficient therapy in these cases. If there is pronounced swelling of the eyelids and discharge of pus, a visit to the ophthalmologist is indicated. These are indications of bacterial conjunctivitis (Fig. 1); antibiotic treatment is usually indicated here.

If a contact lens wearer presents with symptoms such as conjunctivitis, an immediate ophthalmological presentation is indicated. Serious, contact lens-associated infections can lead to a pronounced permanent reduction in visual acuity and even blindness. The question of wearing contact lenses must therefore be asked.

A highly contagious and notifiable viral conjunctivitis is epidemic keratoconjunctivitis, which is caused by adenoviruses and can occur epidemically. The infection takes place via a droplet or smear infection. Affected patients usually present with severe itching, burning, lacrimation, and swollen conjunctiva. The disease often begins unilaterally and (through smear infection) also affects the second eye over time. Serious manifestations of the disease can lead to permanent visual impairment due to the formation of corneal scars or eyelid misalignments and their secondary diseases. The diagnosis is usually made clinically by the ophthalmologist; the use of rapid tests is controversial. Tear substitutes are therapeutically recommended to alleviate the symptoms. B. Aciclovir eye ointment, regular rinsing with an iodine solution shows varying degrees of success. There is no causal therapy.

Because of the high level of contagiousness that exists for 14 days, those affected must observe strict hygienic measures. In particular, hand contact must be avoided at all costs. A disinfectant that detects adenoviruses should be used to disinfect hands.

Seasonal allergic conjunctivitis

Especially in spring, many patients present with reddened eyes, itching and increased tearing. The suspected diagnosis of allergic conjunctivitis is often based on a brief allergy history. Topical antiallergic drugs can be purchased in pharmacies without a prescription and often lead to significant relief of the symptoms. If this is not the case, the patient should be advised to visit an ophthalmologist, as differential diagnoses or concomitant diseases must be ruled out. There are also severe forms of allergic conjunctivitis, which may require immunomodulating therapy.

With inflammation of the eyelid margin (blepharitis, Fig. 2), patients mostly suffer from chronic itching, burning pain and a foreign body sensation on both sides. The eyelids are red and often encrusted, and the conjunctiva can also be red. Since the meibomian glands, which are responsible for the oily portion of the tear film, do not function adequately in this clinical picture, blepharitis is associated with the dry eye. The eyelid margin inflammation is treated with eyelid margin hygiene and lipid-containing tear substitutes, temporarily antibiotic or anti-inflammatory therapy can be beneficial. There are special care products for eyelid margin hygiene, e.g. B. washing lotions. Most patients have been receiving ophthalmological treatment for a long time because of blepharitis, as it is a chronic disease with a high level of suffering. Blepharitis should not only be assessed by the ophthalmologist but also by the dermatologist.

A stye (hordeolum, Fig. 3) describes an acute bacterial inflammation of a Meibomian or Zeiss gland on the eyelid. A stye shows up as swelling and reddening of the eyelid, usually a pressure pain is described. Often a lump on the eyelid can be felt. In most cases, local therapy is e.g. B. with gentamicin / dexamethasone-containing eye ointment is sufficient. In addition, warm compresses can be applied. Sometimes, however, an incision of the stye must be made or systemic antibiotic therapy initiated if the infection spreads (eyelid phlegmon, Fig. 4).


Inflammation of the lacrimal gland (dacryoadenitis) leads to reddening and swelling of the upper eyelid. The lid is tender on pressure and there may be a purulent discharge from the eye. Typically, the upper eyelid has a so-called paragraph shape, which is caused by swelling of the temporal upper eyelid. Dacryoadenitis is mostly bacterial and must be treated with antibiotics and monitored closely. This can also cause an orbital phlegmon (see below) to develop.


If there is reddening and swelling above the lacrimal sac, below the nasal corner of the eyelid, if this region is tender on pressure and if pus empties over the lacrimal points, then dacryocystitis is most likely. Antibiotic therapy, often an abscess splitting and rinsing with iodine solution by an ophthalmologist are necessary. Sometimes patients are hospitalized for monitoring and therapy. Surgical reconstruction of the lacrimal ducts is performed in the non-irritant interval.

Orbital phlegmon

Starting from different sources of inflammation, diffuse bacterial inflammation of the connective tissue of the eyelids can occur. Most of the time the pathogens are staphylococci or streptococci. The eyelids are red, swollen and tender. Systemic antibiotic therapy must now be initiated and an extension of the infection into the orbit must be ruled out. An ophthalmologist has various test criteria for this. If the infection spreads to the orbit, there is a risk of blindness and the patient must be hospitalized.


Very severe, boring, radiating pain and reddening of the eye are symptoms of inflammation of the dermis (sclera). The redness is caused by inflammation of deep scleral vessels and superficial conjunctival vessels. Scleritis can be diffuse or nodular (appearing nodular and localized); it can affect the anterior or posterior sections of the sclera. Around 50% of patients suffer from an underlying systemic disease that is associated with it. If no relevant disease is known, an investigation should be carried out. Depending on the extent, scleritis is treated with antihistamines, nonsteroidal anti-inflammatory drugs, corticosteroids or immunosuppressive therapy. Ophthalmologists should monitor patients because of complications that could impair vision, such as necrosis and thinning of the sclera.

The episclera is a thin, well-vascularized membrane layer that is located between the sclera and the conjunctiva. Inflammation of this membrane layer, episcleritis (Fig. 5), appears similar to scleritis. However, the pain is much less severe and affects younger patients. There is usually no associated underlying disease. The episcleral vessels are inflamed. Mild episcleritis is treated with tear substitutes, a more pronounced finding with local steroids or systemic non-steroidal anti-inflammatory drugs.


Uveitis is an inflammation of the uvea (middle skin of the eye), which consists of the iris, ciliary body and choroid. Depending on which anatomical structures are affected, the nomenclature, the symptoms and the extent of the therapy differ. The most common and well-known manifestation is iritis (iritis).

In the acute stage, patients suffer from a so-called Anterior uveitis pain (often described by the patient as severe pressure pain), sensitivity to light, watery eyes and reduced visual acuity, the eye appears reddened. The Uveitis intermedia is rather painless, patients notice suspended particles in front of both eyes and a decrease in visual acuity. The same symptoms as with anterior uveitis (Fig. 6) can occur in a somewhat less pronounced form. A Posterior uveitis In addition to a reduction in visual acuity, this rarely leads to pain and reddening of the eye.

Any form of uveitis urgently requires a medical assessment to initiate the necessary therapy. In some cases topical therapy is sufficient, in some cases systemic therapy is necessary. The causes are z. B. Infectious diseases, rheumatic diseases, autoimmune diseases, consequences of surgical interventions (differential diagnosis: bacterial endophthalmitis), a clarification should be arranged by the ophthalmologist. Often, however, no clear cause is found.

Keratitis and corneal ulcer

Inflammation of the cornea is called keratitis. Keratitis causes symptoms due to pronounced sensitivity to light (photophobia), pain, increased lacrimation and - depending on the location of the lesion - a reduction in visual acuity. The causes of keratitis are different. It can be induced by mechanical irritation, i.e. by a foreign body, or a malocclusion of the eyelid. Keratitis can also occur as a consequence of a wetting disorder (see keratoconjunctivitis sicca); suspicion of a systemic disease (e.g. collagenoses such as Sjögren's syndrome, lupus erythematosus, etc.) must be clarified accordingly. Chemical irritation, e.g. B. through chemical burns or through drug therapy can lead to keratitis.

Infectious keratitis caused by herpes viruses are common. Herpes simplex keratitis can be diagnosed by the ophthalmologist, for example, on the typical tree-like (dendritic) figure on the cornea. Herpes zoster keratitis is also one of the frequent diagnoses in ophthalmological practice. After an initial infection, often as part of a varicella infection in childhood, the varicella-zoster virus persists in the ciliary ganglion and can be reactivated there. Symptoms of herpes zoster keratitis can appear days before the onset of the typical skin rash. The clinical diagnosis is confirmed at the latest when the rash occurs. Herpes-associated keratitis and other viral and bacterial keratitis must be appropriately diagnosed and treated by the ophthalmologist. Contact lens wearers are particularly at risk for bacterial / parasitic keratitis. In particular, a possible intraocular involvement must also be investigated. If this remains undetected, permanent irreversible damage can result, with a reduction in the patient's eyesight.

Corneal ulcers can develop from almost any keratitis. A so-called Corneal ulcer (Fig. 7) is checked closely by the ophthalmologist. Scars from a corneal ulcer can lead to permanent loss of visual acuity. Increasing thinning of the cornea can lead to perforation of the eye. Perforation is an absolute emergency as it threatens to blind the patient.


An absolute emergency in ophthalmology is an acute increase in intraocular pressure, also popularly known as a "glaucoma attack". The acute increase in intraocular pressure can lead to blindness if left untreated. The patients usually complain of severe pain in the affected eye, the eye is often reddened, the cornea can appear cloudy like frosted glass. The visual acuity and the pupillary reaction in the affected eye are usually reduced.

The causes of an acute increase in intraocular pressure are different. A distinction is made between primary and secondary glaucoma diseases in terms of causes. Primary glaucoma diseases mainly include open-angle and narrow-angle glaucoma, secondary glaucoma can occur, for example, as part of inflammation or drug-induced (e.g. through the use of steroids). Only an ophthalmologist can confirm the diagnosis, determine the cause and initiate appropriate therapeutic measures. Depending on the underlying disease, these range from drug treatment to surgical measures.

The so-called hyposphagma is often confused with conjunctivitis (Fig. 8). This is a ruptured vessel under the conjunctiva, which leads to blood-red, painless, mostly sectorial reddening of the eye. The cause of hyposphagma can be mechanical irritation (rubbing) or increased blood pressure, sometimes in connection with the use of oral anticoagulants. Blood pressure and blood thinning therapies should therefore be checked if hyposphagma occurs repeatedly. A hyposphagma unsettles the patient due to the strong reddening, but is harmless to the eye and heals without consequences.

Red eye - post-operative and post-traumatic

If the patient reports eye trauma or previous eye surgery in connection with acute symptoms in the affected eye, they should see an ophthalmologist immediately.

In the event of trauma, perforation (opening of the skin due to trauma with or without loss of intraocular material), a bone fracture in the area of ​​the eye socket with the risk of entrapment of important structures, superficial injuries, increased intraocular pressure and inflammation of the eye must be excluded.

Especially in the first month after an eye operation, there is a risk of inflammation of the inside of the eye due to the entry of bacteria through the surgical accesses (endophthalmitis). Endophthalmitis requires immediate initiation of systemic broad-spectrum antibiotic therapy as well as surgical removal of the vitreous humor and rinsing of the inside of the eye with antibiotics and corticosteroids. However, bacterial inflammation as a result of the operation can rarely occur even after months or years (e.g. filter cushion inflammation after filtering glaucoma surgery). Other possible complications after an operation, which are associated with pain and reddening of the eye and possibly reduced visual acuity, are z. B. Increased intraocular pressure and corneal surface disorders with the risk of corneal ulcer formation.

The red eye has a variety of possible causes. In order to recognize these and treat them adequately, an ophthalmological examination is required. An anamnesis of the symptoms (Fig. 9), knowledge of the duration of the symptoms, previous medication or concomitant illnesses can provide information on the cause of the symptoms and help to assess the urgency of an ophthalmological examination. Only a few therapy options are available without a prescription. An ophthalmological examination is indicated at the latest when these therapeutic options do not lead to any alleviation of the symptoms. |


Erb C. Drug eye therapy. 6th completely revised and expanded edition 2016, Thieme Verlag

Bagheri N. The Wills Eye Manual. 7th edition, June 2016, Wolters Kluwer

Burk R, Burk A. Checklist ophthalmology. 5th edition 2014, Thieme Verlag

Dr. med. Anna Katharina Paul, Study of human medicine at the University of Ulm and the Université d’Angers, France

2012 to 2013 research work in the central ultrasound of the Ulm University Clinic

Since 2013 employment as an assistant doctor at the Charlottenklinik für Augenheilkunde Stuttgart

2017 PhD at the University Clinic Ulm

Dr. Anna Sophie Moser, Study of human medicine at the University of Ulm

2013 PhD at the University of Ulm

2013 to 2014 internal medicine at the Bad Cannstatt Hospital, Stuttgart Clinic

2014 to 2016 ophthalmology in the Diakonissenkrankenhaus Karlsruhe-Rüppurr

since 2016 Charlottenklinik for Ophthalmology, Stuttgart

Prof. Dr. med. Gangolf Sauder, Study of human medicine at the Friedrich Wilhelm University in Bonn

1996 to 1999 specialist training at the Mittelrhein Foundation Clinic in Koblenz

2000 to 2006 senior physician in charge of the University Eye Clinic Mannheim

since 2006 chief physician at the Charlottenklinik for ophthalmology, Stuttgart

DAZ 2017, No. 39, p. 58, 09/28/2017