A colleague came to work with a black eye. His bruises have nothing to do with work and don't impair him. We are on the same hierarchical level, but work in different teams and on different projects. We see each other every day, but our interactions are usually limited to greetings or small talk. Even though our work-relationship is not too close, it's friendly and he is a nice and respected colleague. Outside of work, we do not meet each other.
My reaction was to greet him and ignore the black eye, when we entered the building. But I wonder what the most appropriate reaction would have been. My goal is to keep it professional and also make the colleague not feel uncomfortable.
What is the professional and appropriate reaction to a not-so-close, but friendly colleague with a black eye?
How to comment on physical changes and alterations of colleague's appearance is somewhat related, but the situations (someone dyed their hair) seem to be too different. I have a black eye. How do I respond to the inevitable curiosity and protect my workplace reputation? is from the point of view of someone with a black eye, who is concerned about their reputation. While questions may be considered annoying, they are afraid of gossip that could rather be the result of people not asking, but guessing.