It is folklore. The mind is a powerful thing and hallucinations can trick you into thinking what you see is real. Even touching what you see can feel real as that is your brain still tricking you. Seek a doctor and tell the doctor about what you are going through. Include frequency, time of day, breathing, stress level, and any other symptoms that happen before, during, and after... Such as nosebleeds, dizziness, nausea, headache, and etc... When you don't get enough sleep especially for a long period of time this can and will effect you physically and mentally.