What can residual corneal opacities from adenovirus conjunctivitis be visible for?

Residual corneal opacities resulting from adenovirus conjunctivitis can indeed be visible for an extended period, potentially up to 2 years. Adenoviral conjunctivitis is known for causing significant inflammation on the ocular surface, which can lead to corneal changes. After the acute phase of the infection resolves, some patients may experience persistent opacities due to the scarring that occurs as a part of the healing process.

These opacities can be a result of the inflammatory response to the virus and can linger long after the initial symptoms have disappeared. Monitoring and follow-up care are essential in these cases, as these opacities may impact visual clarity and require interventions if they significantly affect sight.

In the context of the other choices, shorter durations such as 1 month, 6 months, or even 1 year do not fully encompass the potential longevity of corneal changes caused by this type of conjunctivitis, which can surpass these timelines, hence making the 2-year timeframe the most accurate answer for visibility of residual corneal opacities.