If I unintentionally see something unclean, are my prayers and fasting acceptable?

Seeing dirt does not affect the validity of prayer or fasting. As for indecencies or lustful thoughts, if they occur unintentionally, they do not affect fasting or prayer, unless they lead to the emission of madhi (pre-seminal fluid) or mani (seminal fluid); in which case, ritual purity is invalidated, and prayer is not valid until one purifies themselves. However, fasting is not invalidated by the first glance, but if repeated looking leads to the emission of mani, the fast is invalidated and a make-up day is required. The emission of madhi, however, does not invalidate the fast.