Can influenza A cause red eyes?

H1N1 influenza may present with red eyes as a symptom. Infection with the H1N1 influenza virus can lead to ocular symptoms such as conjunctival congestion, tearing, and eye pain, which are very similar to those of the common cold. If a patient with H1N1 influenza develops conjunctivitis simultaneously, redness of the eyes is one of the common manifestations. Conjunctivitis may result from direct viral infection of the eye or indirect transmission, such as touching the eyes with contaminated hands. The presence of red eyes does not necessarily indicate H1N1 influenza, as it may also be caused by other diseases or factors. To prevent ocular symptoms such as red eyes due to H1N1 influenza, patients are advised to maintain good eye hygiene during illness, avoid rubbing their eyes, and seek timely medical attention for antiviral treatment under a doctor's guidance.