Understanding Conjunctivitis

Conjunctivitis, often referred to as pink eye, is a common eye condition that affects millions of people worldwide. It's an inflammation or infection of the transparent membrane (conjunctiva) that lines your eyelid and covers the white part of your eyeball. This condition can be quite uncomfortable, but it rarely affects your vision. Schools and daycare centres are often hotspots for the bacterial and viral types of conjunctivitis because the infection spreads through direct contact.

Causes of Conjunctivitis

There are several causes of conjunctivitis, each resulting in similar symptoms. Let's delve into the main types:

  • Bacterial Conjunctivitis: This type is caused by bacteria, such as Staphylococcus aureus or Haemophilus influenza. It can occur in one or both eyes and is often associated with an infection in the respiratory tract.
  • Viral Conjunctivitis: This is the most common cause of conjunctivitis. It's usually caused by the same viruses that cause the common cold. Just like a cold, this type of pink eye can be very contagious.
  • Allergic Conjunctivitis: This type occurs when your body reacts to a foreign substance (allergen), such as pollen or dust mites. Both eyes are usually affected in allergic conjunctivitis.
  • Irritant Conjunctivitis: This type is caused by irritants such as chlorine, smoke, or certain cosmetics. It can cause your eyes to become red and produce more tears.

Symptoms of Conjunctivitis

The symptoms of conjunctivitis can vary depending on the cause, but there are some common signs to look out for:

  • Redness in one or both
  • Itchiness in one or both eyes
  • A gritty feeling in one or both eyes
  • Tearing
  • A discharge from one or both eyes that forms a crust during the night

In the case of bacterial conjunctivitis, you might notice a heavy yellow or greenish discharge, while viral conjunctivitis often produces a lighter, watery discharge. Allergic conjunctivitis, on the other hand, is usually accompanied by intense itching, tearing, and inflammation of the eyes, often accompanied by other allergy symptoms such as a runny nose. If you're experiencing any of these symptoms, it's essential to seek medical advice to determine the cause and appropriate treatment.

Diagnosis of Conjunctivitis

If you suspect you have conjunctivitis, it's crucial to get a proper diagnosis. This usually involves a clinical examination by a healthcare provider. They'll ask about your symptoms and medical history, and they may perform a physical examination of your eyes.

In some cases, they may use a cotton swab to take a sample of fluid from your eyelids to be analyzed in a lab. This can help determine whether your conjunctivitis is caused by a virus, bacteria, or an allergy. For more information on how conjunctivitis is diagnosed, you can visit this resource.

Treatment of Conjunctivitis

The treatment for conjunctivitis depends on the cause:

  • Bacterial Conjunctivitis: This type is usually treated with antibiotic eye drops or ointments, also known as chloramphenicol, that you apply directly to your eyes. You might need to use these several times a day for a week or two.
  • Viral Conjunctivitis: Unfortunately, there's no specific treatment for viral conjunctivitis. Like a common cold, the virus has to run its course, which can take one to two weeks. Applying a cold compress to your eyes can help alleviate symptoms.
  • Allergic Conjunctivitis: If allergies are the root cause of your conjunctivitis, you might be prescribed anti-allergy medications, such as antihistamines. These can be in the form of eye drops, oral medications, or nasal sprays. Avoiding the allergen is also a crucial part of treatment.
  • Irritant Conjunctivitis: For this type, it's best to avoid the irritant causing the inflammation. Your eyes should start to improve once the irritant is removed. If your eyes are very red and painful, seek medical attention.


Prevention of Conjunctivitis

Preventing conjunctivitis is often a matter of good personal hygiene and a few simple precautions. Here are some tips:

  • Hygiene Practices: Wash your hands often with soap and warm water. If soap and water are not available, use an alcohol-based hand sanitiser. Avoid touching or rubbing your eyes unless your hands are clean.
  • Avoiding Allergens: If you have allergic conjunctivitis, try to avoid the allergens that trigger your symptoms. This might mean staying indoors on high pollen count days or getting special covers for your pillows and mattresses to keep out dust mites.
  • Proper Use of Contact Lenses: Follow your eye doctor's instructions for contact lens care. Use a clean lens case, replace your lenses as recommended, and never wear someone else's contact lenses.

Remember, prevention is always better than cure. For more detailed information on how to prevent conjunctivitis, you can check out this resource.


Let's address some frequently asked questions about conjunctivitis:

  • Is conjunctivitis contagious? Yes, bacterial and viral conjunctivitis can be highly contagious. They can spread through direct or indirect contact with the eye secretions of someone who's infected. Allergic and irritant conjunctivitis are not contagious.
  • How long does conjunctivitis last? The duration of conjunctivitis depends on its cause. Bacterial conjunctivitis usually improves within a week with appropriate treatment, while viral conjunctivitis can last one to two weeks. Allergic conjunctivitis will last as long as you're exposed to the allergen.
  • Can conjunctivitis come back? Yes, especially if you're exposed to the same bacteria, virus, or allergen that caused it in the first place. Good hygiene practices can help reduce your risk.
  • When should I see a doctor for conjunctivitis? You should see a doctor if you have severe pain, your vision is affected, your symptoms don't improve after a week, or your symptoms get worse. If you have a weakened immune system, for example, due to HIV or cancer treatment, you should seek medical attention immediately if you suspect you have conjunctivitis.


Written by Christian Jakobsson