Amped up word(s) of the day(from a nontraditional source)!

Hallucination
1. a sensory experience of something that does not exist outside the mind, caused by various physical and mental disorders, or by reaction to certain toxic substances, and usually manifested as visual or auditory images.
2. the sensation caused by a hallucinatory condition or the object or scene visualized.
3. a false notion, belief, or impression; illusion; delusion.



Imagination
1. the faculty of imagining, or of forming mental images or concepts of what is not actually present to the senses.
2. the action or process of forming such images or concepts.



Where is there a line to be drawn between imagination and hallucination?(No, seriously, I need to know, it's important.)