Quote from: DarkMind
Yin-yang eye: can only see lower-plane entities (ghosts, demons, and other negative plane entities)
Divine Eye: can see beings from all dimensions (besides seeing everything that the 3rd eye can see, the Divine Eye can also see higher-level entities such as devas/angels).
Here is an interesting writing about different levels of 3rd eye:
http://www.falundafa.org/book/eng/zfl_new_2.html
"Buddhists talk about the five powers: Flesh Vision, Divine Vision, Wisdom Vision, Law Vision, and Buddha Vision."
Third eye can be according to text "activated" by other entity so that the eye isn't actually open but we're seeing things through entity that is attached to us.. In healing case the entity in our back "heals" with it's hands while we think we're doing it.
Maybe those reiki masters are attaching those entitys to us?
It's not a real healing ability.