Red eyes - what are the causes and what helps?
In most cases, reddening of the eye is due to vasodilation, which is caused by irritation, inflammation or increased intraocular pressure. Allergies, conjunctivitis, corneal or rainbow inflammation can be the cause of the reddened eye, but also glaucoma ("glaucoma") or acute eye injuries. In addition, red eyes are sometimes a sign of tiredness and dry eyes.
Causes of red eyes
Red eyes are a common problem that can affect one or both eyes. The reddening usually arises from blood vessels on the surface of the eye, which are widened by a form of irritation or infection. An injury to the blood vessels with corresponding bleeding in the eye can also cause reddening of the eye. Possible triggers for red eyes include:
- Allergies (especially hay fever),
- Foreign body in the eye,
- Complication with contact lenses,
- Conjunctivitis (conjunctivitis),
- Blepharitis (eyelid inflammation),
- Keratitis (inflammation of the cornea),
- Corneal ulcers and injuries,
- Inflammation of the iris (iritis),
- Uveitis (inflammation of the eye skin),
- Subconjunctival hemorrhage (broken blood vessels in the eye, hyposphagma),
- Dry eyes (reduced tears),
- Eye sores.
Red eyes - a medical emergency?
Under certain circumstances, red eyes can also indicate a medical emergency, in which the emergency services should be contacted immediately. This applies, for example, accompanied by:
- suddenly waning eyesight,
- severe headache,
- Eye pain,
- extreme sensitivity to light,
- Nausea and vomiting,
- Swelling in or around the eye,
- Eye contact with chemicals,
- penetrated foreign bodies,
- optical illusions (hallucinations, flashes of light, etc.),
- and / or if the eye cannot be opened or kept open.
Short-term reddening of the eyes is generally not a cause for concern, but you should react urgently if the reddening of the eyes does not go away after a few days or if there are further symptoms. A specialist examination by an ophthalmologist is essential here.
If the reddened eyes appear after an eye operation or an eye injection, contact the doctor treating you immediately to clarify possible damage to the eye.
Eye redness due to hyposphagma
Extensive bleeding with no visible veins in the whites of the eyes is usually a so-called hyposphagma. This is caused by bleeding under the conjunctiva due to ruptured blood vessels. Possible causes include a sudden increase in blood pressure, for example when sneezing, a generally high blood pressure, injuries to the eye, but also, for example, special, particularly severe forms of viral conjunctivitis.
Eye redness in inflammatory processes
The inflammation can be triggered physically, chemically, allergically, bacterially, virally or by fungi. A distinction must be made between conjunctivitis (conjunctivitis) and corneal inflammation (keratitis) from the underlying inflammation of the iris and ciliary body (iridocyclitis).
Red eyes due to conjunctivitis
With conjunctivitis, the eye is colored bright red and the individual blood vessels in the whites of the eyes are clearly visible. The redness is particularly intense on the outside, towards the eyelids and the corners of the eyes. If only the cornea is affected, reddening dominates towards the middle.
Red eyes due to iritis
If no individual vessels are recognizable and if the conjunctiva shows a bluish-red color at the edge of the cornea, inflammation of the iris and ciliary body is more likely. The iris (the area with the color pigments that determine our eye color) then also appears cloudy. In acute glaucoma, all signs can appear mixed.
Red eyes - diagnosis and treatment
The therapy is based on the underlying disorder, which is also determined taking into account other eye complaints (e.g. visual disturbances, accompanying eye pain), known allergies (e.g. pollen allergy), previous accidents, infections of relatives, general symptoms. Furthermore, for diagnosis - depending on the need - for example, eye tests, examinations with a slit lamp, intraocular pressure measurements (tonometry) and an eye mirror.
The treatment varies depending on the causes of the reddening of the eyes. Bacterial infections can be treated with antibiotic eye drops or antibiotic ointments, for example, while viral infections can sometimes only be treated with poor medication. In the event of acute injuries or foreign bodies in the eye, surgical intervention may also be required. In many cases, however, there is no serious cause for the reddening of the eyes and this goes back on its own over time, with even major bleeding, such as a hyposphagma, being completely eliminated by the body. (jvs, fp)
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Author and source information
This text corresponds to the requirements of the medical literature, medical guidelines and current studies and has been checked by medical doctors.
Jeanette Viñals Stein, Barbara Schindewolf-Lensch
- Pschyrembel Online: Glaucoma (accessed: August 14, 2019), glaucoma
- Ilse Strempel: Glaucoma - more than an eye problem: guide for patients with "glaucoma", Kaden Verlag, 2017
- Uwe Pleyer: Inflammatory Eye Diseases, Springer, 2014
- M. Bruce Shields; Günter K. Krieglstein: Glaucoma: Fundamentals of differential diagnosis therapy. Springer, 2011