Recognizing and Properly Treating Conjunctivitis Symptoms—How to Treat Red Eyes Caused by Conjunctivitis, Including Possible Causes and Treatment

Conjunctivitis is an eye condition, also known as pink eye. It affects the conjunctiva.

This is the thin mucous membrane of the eye that covers the inside of the eyelids and, in part, the eyeball. In conjunctivitis, this conjunctiva is inflamed or irritated.

In general, conjunctivitis can be divided into two types:

• Contagious, infectious conjunctivitis (caused by bacteria, viruses, or fungi), and
• Non-contagious, non-infectious conjunctivitis (usually caused by allergies or external factors)

The conjunctiva contains many blood vessels and responds to inflammation and irritation with increased blood flow. Red eyes are therefore the main symptom of conjunctivitis.

Red eyes are the main sign of conjunctivitis © Birgit Reitz-Hofmann

Conjunctivitis is one of the most common eye conditions and the main cause of red eyes.

Children and infants are often affected, as contagious viral strains spread quickly in daycare centers and schools.

Conjunctivitis can have both infectious and non-infectious causes.

The infectious form of conjunctivitis is highly contagious and can be caused by various pathogens.

Possible causative bacteria include, among others:

• Neisseria gonorrhoeae
• Pneumococci
• Staphylococci, and
• Chlamydia

Viral pathogens that frequently cause conjunctivitis include:

• Adenoviruses
• Herpes viruses
• Influenza viruses and
• Zoster viruses

The most common non-infectious causes of conjunctivitis include allergies and external environmental irritants. This form of conjunctivitis is not contagious. For example, allergies to pollen, food, or medications can cause conjunctivitis.

External irritants that are frequently responsible for conjunctivitis include, above all:

• Drafts (e.g., when driving with the window open)
• Foreign objects or dust in the eye
• Smoke (e.g., when in heavily smoke-filled rooms) or
• Ultraviolet light (e.g., during winter sports or excessive sun exposure)

In some cases, conjunctivitis can also occur as a symptom accompanying other eye conditions. 

These include, for example:

• Disorders of the lacrimal system, such as narrowed or blocked tear ducts
• Recurrent eye infections and
• "Dry eye," which occurs when the natural protective layer on the eye’s surface—the tear film—is disrupted

Depending on the cause, conjunctivitis can manifest with various symptoms. As described, the main symptom of conjunctivitis is redness of the eyes. The conjunctiva responds to inflammation and irritation by increasing blood flow through its many blood vessels.

Other common symptoms include:

• Increased tear production
• Itching or a burning sensation in the eye, as well as
• A sensation of pressure in the eye

In addition, the conjunctiva and sometimes the eyelids are swollen. The eye may discharge a watery, whitish-yellow, mucous, or purulent secretion. This can lead to sticky eyelids, especially in the morning. Increased sensitivity to glare or light is also possible

This is often accompanied by a sensation of a foreign body: Those affected feel as though there are grains of sand in their eyes that rub against each other with every blink.

An ophthalmologist can easily make the diagnosis based on the typical symptoms. However, simply identifying the condition is not enough. To ensure effective treatment, it is necessary to identify the cause and extent of the disease.

To do this, the doctor examines the eye and the inside of the eyelids using a slit lamp. This device allows the eye to be viewed magnified under specific lighting conditions. The doctor also tests visual acuity and, if necessary, examines the back of the eye.

If bacterial conjunctivitis is suspected, the doctor takes a swab from the conjunctiva. The swab is then examined. In the laboratory, it is possible to determine which bacterial pathogen is causing the disease. Such a conjunctival swab can also rule out conjunctivitis caused by viruses or allergies.

An allergy test can also determine whether a specific allergy caused the conjunctivitis. If necessary, additional diagnostic procedures may be used to rule out other serious eye diseases as the cause.

The treatment of conjunctivitis depends on the following factors:

• Severity
• Progression and
• trigger of the condition

Only once the causes of conjunctivitis are known can the ophthalmologist prescribe the appropriate medication.

In cases of bacterial conjunctivitis, antibiotic eye drops or ointments are typically used. These are intended to kill the pathogens. The doctor may also treat severe conjunctivitis with corticosteroid ointments. If the inflammation is caused by dry eye, artificial tears in drop or gel form can help.

The patient instills them into the conjunctival sac, thereby helping to moisturize the surface of the eye. These artificial tears also help with external irritants such as dust, strong sunlight, or allergens. Allergy-related conjunctivitis can be treated with special eye drops containing an anti-allergic active ingredient. In addition, it is advisable in this case to avoid the substances that trigger the allergy (allergens) whenever possible.

Doctors typically treat conjunctivitis caused by herpes or zoster viruses with the active ingredient acyclovir. It suppresses the replication of the viruses. Conjunctivitis that develops as part of a cold due to cold viruses usually does not require treatment. The burning and itching in the eyes associated with conjunctivitis can be relieved by applying cold compresses. Cotton pads or compresses can be used for this purpose.

Infectious conjunctivitis can be prevented by washing your hands regularly. This can help prevent infection, especially after coming into contact with someone who already has conjunctivitis.

If you have an allergy that triggers conjunctivitis, you should avoid the allergen (e.g., pet dander). For seasonal allergens like pollen, taking antiallergic medications in a timely manner can help.

People with dry eyes should ensure they drink enough fluids (about 1.5 to 2 liters daily). Sunglasses protect the eyes from conjunctivitis caused by strong sunlight (such as when skiing), dust, smoke, or drafts.

You should clean your contact lenses regularly and thoroughly. Avoiding eye strain caused by spending too much time in front of a computer or by lack of sleep can also help prevent conjunctivitis.

If conjunctivitis is caused by known factors such as allergies, a cold, drafts, or smoke, a doctor’s visit is not necessary.

In such cases, those affected can use artificial tears and wait to see if the symptoms subside.

However, red eyes can also be a sign of serious eye diseases or bacterial infections that require professional treatment.

Therefore, you should see an ophthalmologist immediately if you experience the following symptoms:

• Sticky, yellowish discharge coming from the corners of the eyes
• Vision problems, such as blurred vision or sudden “blind spots”
• Severe, deep-seated eye pain
• Accompanying symptoms such as fever, nausea, and vomiting

Conjunctivitis is a common condition affecting the conjunctiva of the eye that can be triggered by various factors. Infectious conjunctivitis is usually caused by bacteria or viruses, while non-infectious conjunctivitis is often caused by allergies or irritants. It is important to recognize the symptoms of conjunctivitis early on, as typical symptoms such as redness, itching, or discharge may occur. Particular caution is advised with viral conjunctivitis or purulent conjunctivitis, as these forms are easily transmitted.

The causes of conjunctivitis are varied, and both the causes and treatment differ depending on the type of conjunctivitis. Bacterial or viral conjunctivitis often requires targeted treatment with antibiotic eye drops. Eye drops or eye ointments help alleviate symptoms and support the healing process. In many cases, conjunctivitis usually clears up on its own; however, if conjunctivitis is suspected, medical treatment should be sought.

Simple home remedies can also be helpful, though hygiene plays a key role. Towels and washcloths should not be shared to prevent infection. Conjunctivitis can also be caused by external factors when pathogens enter the eye. Therefore, it is important to be aware of potential triggers that can cause conjunctivitis or exacerbate an existing case.

When initial symptoms appear or additional symptoms develop, it is important to determine the specific type of conjunctivitis. Chronic conjunctivitis or persistent symptoms always require a more thorough examination. Treatment for conjunctivitis depends on the specific cause and should be tailored to the individual.

In summary: Recognizing and properly assessing conjunctivitis is crucial to preventing complications. Whether you should see a doctor depends on the severity of your symptoms. Conjunctivitis should be taken seriously, even though it is often harmless. With the right treatment, conjunctivitis can heal quickly and symptoms can be effectively relieved.

What are the typical symptoms of conjunctivitis?
Typical symptoms of conjunctivitis include a red eye, itching, burning, a sensation of a foreign body, and eyelids that stick together due to discharge. The severity of these symptoms can vary depending on the cause.

Is conjunctivitis contagious?
Infectious conjunctivitis, caused by a virus or bacteria, is contagious. Transmission can occur quickly, particularly through towels and washcloths, which is why good hygiene is important.

What causes conjunctivitis?
The causes of conjunctivitis are varied. Viruses or bacteria are often responsible, but allergies, irritants, or contact lenses can also trigger inflammation of the conjunctiva.

How is conjunctivitis treated?
Treatment for conjunctivitis depends on the cause. Antibiotic eye drops are used for bacterial conjunctivitis, while anti-allergy medications are effective for the allergic form.

When should you see a doctor for conjunctivitis?
You should see an ophthalmologist if your symptoms are severe, persist for a long time, or worsen. It’s also advisable to seek medical evaluation if you suspect you have contagious conjunctivitis or if the patient is a child.