Conjunctivitis can be categorized by the speed of onset into hyperacute, subacute, acute, and chronic types. It can also be classified by severity into mild, moderate, and severe. Acute conjunctivitis usually is self-limiting, with the condition lasting about two weeks. Effective localized treatment and administration of sensitive antibiotics can lead to recovery within a few days. In contrast, chronic conjunctivitis is not self-limiting and is more challenging to treat.