Viral infections of pink eye typically clear up in one to two weeks without treatment and without any long-term consequences. However, in some cases, viral conjunctivitis can take longer than three weeks to clear up.

Bacterial pink eye is caused by an infection with bacteria and can be treated with antibiotics. The prescribed course of drugs should start clearing up the infection within 24 hours of the first dose, as long as they are taken as prescribed. Even if a person does not use antibiotics, mild bacterial pink eye often improves within 10 days. However, it does have the potential to develop into more serious symptoms, so treatment is often recommended.

Bacterial and viral conjunctivitis are both highly contagious, and adults may be contagious for up to two weeks after the first symptoms appear, however the contagious period may last as long as three to four weeks. Allergic conjunctivitis is not contagious and cannot be spread from person to person; instead, it is caused by an allergic reaction, such as from pollen, pet dander, dust mites or even certain foods.

Pink eye can sometimes heal on its own, but it usually takes a while to resolve without treatment. The underlying cause of the condition determines how long it takes to go away. It usually takes 1 to 3 weeks for pink eye to go away if a viral infection is the underlying cause. If a bacterial infection is the cause, it may take even longer for the condition to resolve.

It is possible to develop pink eye overnight, as the condition can be caused by various factors and often develops rapidly. The most common cause of pink eye is a viral or bacterial infection, which can spread easily through contact with contaminated hands and objects.

Furthermore, you are more likely to contract pink eye if you were in close proximity to someone who has the infection. In addition, exposure to irritants or allergens such as pollen, dust or smoke, as well as prolonged contact lens wear without proper cleaning, can result in pink eye.

Pink eye can also result from an underlying medical condition, such as dry eyes, or as a side effect of certain medications.