What is a common cause of conjunctivitis?

Conjunctivitis, commonly known as pink eye, is most often caused by either an infection or an allergic reaction. In terms of infectious conjunctivitis, it can be viral or bacterial, with viral conjunctivitis being quite common and often linked to colds or respiratory infections. Bacterial conjunctivitis, on the other hand, can result from various bacterial infections and is characterized by symptoms like redness, itching, and discharge. Allergic conjunctivitis occurs in response to allergens such as pollen, dust mites, or pet dander, leading to watery, red, and itchy eyes.

Other potential causes such as excessive screen time may lead to eye strain or discomfort but are not typically associated with conjunctivitis itself. Chronic skin conditions might impact the skin around the eyes but do not generally lead to conjunctivitis. Blepharitis is inflammation of the eyelid margins and can sometimes contribute to discomfort or irritation but is not a direct cause of conjunctivitis either. Therefore, identifying infection or allergy as the common cause accurately encompasses the main etiologies related to this eye condition.