Interesting question. I found this--
www.baus.org/baus/library/5eyese.html
-- cited in this blog:
knockingfrominside.blogspot.com/2006/08/...yes-of-buddhism.html
as follows:
"Briefly, the five eyes referred to are not actual eyes; rather, they represent levels of understanding, different modes of perceiving reality.
The “physical eye” represents normal perception, which all physical beings share to some extent.
The “heaven eye” is still a purely physical perception, but can see further and deeper; C.T. Shen compares the heaven eye to the use of microscopes and various remote-sensing technologies.
The “wisdom eye” perceives the illusory nature of reality and penetrates to emptiness.
The “Dharma eye” acknowledges the truth perceived by the wisdom eye. However, the Dharma eye also sees that the suffering experienced by beings embedded in the illusion of reality is real to them; the Dharma eye is compassionate. It’s from this compassionate perception that the oath of the Boddhisatva arises: “Though sentient beings are numberless, we vow to save them all.”
Finally there is the “Buddha eye”. This perception is not describable or comprehensible in ordinary human terms; it can only be experienced. "