The act of changing faith usually brought about by religious experience. Such as I see in a dream a pink hippo. The pink hippo tells me that it is God. And thus I form a religion worshipping pink hippos. This would be a conversion to hippoism.
An imaginary vision is a vision that happens within the mind's eye. Such as Jobe's ladder, he saw a ladder to heaven in a dream, and he climbed it.
You see the vision in physical form, such as seeing Moses seeing the burning bush.
A sudden realisation of the truth that culminates in a new understanding of something, such as the Bhudda's enlightenment wher he achived a a new understanding of the metaphysical dichotomy of reality
Sense of ineffable awe. Experienced with a religious experience, cataclysm and metastorm of emotions.