Why are my dad's droopy eyelids caused by Parkinson's drooping even worse after Botox treatment to eyelids? (photo)

Thank you for your question. A before photo would be helpful. Botox can migrate into muscles where it was not intended and you receive the above result. It will wear off in approx. 3 months. Best, 

The. Botox has migrated to Muller's muscle, which lifts the upper eyelid. This will wear off, and in the meantime he may be able to use apresoline drops to lift the eyelid.

When people have ptosis (eyelid or eyebrow droopiness) Botox must be done extremely conservatively and in just the right places or the ptosis can get much worse. This is what happened for your father. Sometimes reinjecting in other areas can help lift it again, but sometimes it's just best to wait for it to wear off. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."