How is Conjunctivitis Caused?

Conjunctivitis, commonly known as “pink eye,” is the inflammation of the conjunctiva, which is the clear membrane that covers the white part of the eye and lines the inner surface of the eyelids. Conjunctivitis can be caused by various factors, and the most common causes include:

  • Viral Infections: Viruses, particularly adenoviruses, are a common cause of viral conjunctivitis. Adenoviruses are the same viruses that can cause respiratory infections, such as the common cold. Viral conjunctivitis is highly contagious and can be spread through direct or indirect contact with the eye secretions of an infected person.
  • Bacterial Infections: Bacterial conjunctivitis is often caused by bacteria such as Staphylococcus aureus, Streptococcus pneumoniae, or Haemophilus influenzae. Bacterial conjunctivitis can be transmitted through direct contact with infected eye secretions or by touching surfaces contaminated with the bacteria.
  • Allergic Reactions: Allergic conjunctivitis is triggered by exposure to allergens such as pollen, dust mites, pet dander, or certain chemicals. It is not contagious and often affects both eyes. Allergic conjunctivitis is more common in individuals with a history of allergies.
  • Irritants: Exposure to irritants like smoke, pollution, chlorine in swimming pools, or harsh chemicals can lead to irritant conjunctivitis. This form of conjunctivitis is not infectious and is caused by direct irritation of the conjunctiva.
  • Foreign Bodies: Particles or foreign bodies, such as dust or sand, entering the eye can cause mechanical irritation and inflammation, leading to conjunctivitis.
  • Contact Lens-Related Irritation: Improper use, cleaning, or wearing of contact lenses can increase the risk of developing conjunctivitis. Bacterial or allergic reactions can occur in association with contact lens use.

The symptoms of conjunctivitis can include redness, itching, burning, tearing, and a discharge from the eyes. The type of conjunctivitis and the appropriate treatment depend on the underlying cause. Viral conjunctivitis is typically self-limiting and may not require specific treatment, while bacterial conjunctivitis may be treated with antibiotic eye drops or ointments. Allergic conjunctivitis may be managed with antihistamines or other allergy medications.

To prevent the spread of contagious conjunctivitis, it’s important to practice good hygiene, such as frequent handwashing, avoiding touching the eyes, and not sharing personal items like towels or pillows. If someone suspects they have conjunctivitis, especially if it is associated with significant discomfort or vision changes, it is advisable to seek medical attention for proper diagnosis and appropriate management.