"If I hadn't seen it with my own eyes, I would not have believed either." — Lorekeeper Aeron
Visual hallucinations are the main way a lot of the supernatural beings tend to communicate with their surroundings. Languages are hard, not everyone is able to read and write either, so for many beings out there, sending visions is the only way they are able to communicate with most of the humans on the island. It is also a favoured way to communicate among magicians and other magically inclined folks, as it is quick and almost undetectable, therefore it is possible to send messages to people in secret. Only those with more magical prowess are able to actually influence someone with the visions and manipulate them in whichever way they please. Those visions tend to be more detectable as those under their influence start behaving weirdly, often opposite their natural instincts or personality.
Visions are not restricted to only one discipline of magic. As human brains receive most of their information by sight, it is just the most common manifestation, the most common result of beings outside their scope of understanding trying to send them a message. Sentient inhabitants of the forests and other wild areas of the island use them, as well as the holy Icons, that are sending complicated messages to their chosen priests and saints. Some of the most famous visions received by people were further immortalised as glass mosaics in cathedrals or as paintings and tapestries in the castles. It is common for lords and ladies to commission their makings after a miracle happens in their domain.
Visions are always without, sometimes a static image, other times an entire animated scene similar to a dream state, or visual hallucination enhancing the reality around the one who is on the receiving end of a vision. Poeple skilled in receiving visions might be able to identify who has send them as different beings have a slightly different style, some might say, a signature.
