Symptoms and Causes

What are the symptoms of conjunctivitis?

The most common conjunctivitis (pink eye) symptoms include:

• Redness in the eye.
• Mild fatigue.
• Itching or irritation
• Sneezing.
• Runny or stuffy nose.
• Low-grade fever.
• Head and body aches.

Different types of conjunctivitis

Conjunctivitis comes in different types, each with its own cause and symptoms. The five main forms are

• Infectious Conjunctivitis: Infectious conjunctivitis is a type of pink eye caused by bacteria or viruses. It spreads easily from person to person, especially in crowded places like schools or homes. The infection is passed through touch, shared items, or contact with eye discharge. This is why pinkeye can move so quickly among family members or classmates.
• Bacterial Conjunctivitis: Bacterial conjunctivitis occurs when bacteria infect the eye. It often begins in one eye and spreads to the other. A common sign is thick yellow or green discharge, which may cause the eyelids to stick together after sleeping. This type usually improves with antibiotic eye drops and should be treated promptly to avoid complications.
• Viral Conjunctivitis: Viral conjunctivitis is caused by viruses, similar to those that cause colds or flu. It is highly contagious and often appears alongside symptoms like a sore throat or runny nose. The discharge is usually watery, and the infection clears on its own over time without antibiotics.
• Allergic Conjunctivitis: Allergic conjunctivitis happens when the eyes react to allergens such as pollen, dust, or pet hair. It is not contagious. Symptoms often include itchy, red, watery, and swollen eyes. Avoiding triggers and using allergy medications can help manage the discomfort.
• Irritant Conjunctivitis: Irritant conjunctivitis develops when the eyes are exposed to irritants like smoke, chemicals, or polluted air. It is not an infection and does not spread to others. Washing the eyes and staying away from the irritant usually helps relieve symptoms.

What causes conjunctivitis?

Conjunctivitis, commonly known as pink eye, can develop for several reasons. The most common causes include the following:

• Bacterial Infections: Bacterial infections occur when germs such as Staphylococcus aureus or Streptococcus pneumoniae enter the eye. This often leads to redness, eye pain, and thick discharge that may cause the eyelids to stick together. Because bacterial conjunctivitis can worsen or cause complications, medical treatment is usually needed to clear the infection.
• Viral Infections: Viral conjunctivitis is commonly linked to colds, sore throats, and other respiratory infections. It spreads very easily through coughing, sneezing, or close contact. Even simple actions like shaking hands or sharing makeup or towels can pass the virus from one person to another.
• Allergens: For people with allergies, substances such as pollen, pet dander, dust mites, and mold can trigger conjunctivitis. When the eyes react to these allergens, they may become red, itchy, watery, and swollen. While uncomfortable, this type of conjunctivitis is not contagious.
• Irritants: Irritant conjunctivitis happens when the eyes are exposed to smoke, chlorine from swimming pools, or chemical fumes. Symptoms often appear quickly and may include burning, redness, or watering of the eyes. Once the irritant is removed and the eyes are rinsed, the discomfort usually improves.
• Poor Hygiene: Touching the eyes with unwashed hands, sharing towels, makeup, or contact lenses can increase the risk of developing conjunctivitis.​
• Contact Lens Use: Wearing contact lenses for long periods, poor lens hygiene, or using contaminated lens solutions can lead to eye irritation or infection.​

Diagnosis of conjunctivitis

An ophthalmologist can usually diagnose conjunctivitis by examining the eye and identifying whether it is viral or bacterial.

• Medical History: The ophthalmologist asks about eye-related symptoms such as redness, discharge, itching, pain, light sensitivity, or blurred vision. They may also ask about
  recent eye infections, colds, allergies, contact lens use, exposure to irritants, or contact with someone who has pink eyes.
• Visual Acuity Test: The ophthalmologist checks whether conjunctivitis has affected your vision by testing how well you can read letters or symbols from 20 feet away, one eye at a time.