If you prayed without wudu by mistake, you have to do wudu and repeat your prayer. There is no sin on you if you were unaware of that. If you were aware that you had broken your wudu and that it was haram for you to pray in this situation, then you have committed a grave sin.

The scholars agreed that it is disliked to close the eyes in prayer unless there is a reason for doing so, such as fear of seeing something one should not be looking at while praying, such as seeing one’s wife, or a non-mahram woman, naked.