What condition is indicated by unilateral then bilateral purulent eye discharge without pain or visual disturbance?

Unilateral then bilateral purulent eye discharge without pain or visual disturbance is indicative of bacterial conjunctivitis. This condition typically presents with thick, yellow-green discharge from the eye, which can start in one eye and then spread to the other. The discharge is usually significant enough to cause the eyelids to stick together, especially after sleep.

In bacterial conjunctivitis, the absence of eye pain and visual disturbances is consistent with a mild presentation, as the primary symptom is often related to discharge. Unlike allergic conjunctivitis, which would present more with itching and redness rather than discharge, and viral conjunctivitis, which often includes watery discharge, bacterial conjunctivitis is characterized specifically by the purulent nature of the discharge.

Chlamydial conjunctivitis could also present with discharge, but it often comes with additional complications and symptoms, such as a more insidious onset and possible pain, which are not present in this scenario. Thus, given the described symptoms, bacterial conjunctivitis is the most fitting diagnosis for this situation.