How long for conjuctivities heal?

Depends: This depends on the type of conjunctivitis. Usually it can take up to two weeks to resolve completely. Some types of conjunctivitis like bacterial or allergic respond to medication, but some (like viral conjunctivitis) do not respond to medication and will just resolve on their own. If it persists for more than 10-14 days then i would see your eye physician.

2-3 weeks: It could be as long as 2-3 weeks depending on the cause. With allergic conjuctivits, the stimulus to conjuctivitis may still be present so it is harder to resolve.