Which eye condition is commonly referred to as "pink eye"?

"Pink eye" is commonly known as conjunctivitis, which is an inflammation of the conjunctiva, the clear membrane that lines the eyelid and covers the white part of the eyeball. This condition can be caused by various factors, including viral or bacterial infections, allergies, or irritants. The symptoms typically include redness, itching, discharge, and watering of the eyes, which give it the characteristic "pink" appearance.

In contrast, strabismus refers to a condition where the eyes are not properly aligned with each other, which can lead to double vision or amblyopia but does not cause the redness associated with conjunctivitis. Cataracts involve clouding of the lens of the eye and are associated with vision loss, not eye redness. Diabetic retinopathy is a complication of diabetes that affects the retina and can lead to severe vision problems, but again, it does not present as "pink eye." Hence, the reason for identifying conjunctivitis as "pink eye" is deeply rooted in its defining characteristics and symptoms.