Yes, it is.
You are likely to suffer from itchy eyes, when you stay in a damp place for too long. That's because mold often arises from damp places on the walls, corners or wooden structures. People may suffer from allergies because of the mold. It makes you have itchy eyes and sneezing nose.
Even if there is no mold at all, it could be dangerous for people to stay in damp places. As the air is humid and laden with hydrone, who knows what there are in the hydrone. Maybe bacteria, virus, fungas, dust, and so on. Some of the bacteria are extremely harmful to your eyes.