Guru Goggles

Noun. Guru Goggles are not physical. They are metaphorical, and refer to the way in which people become devoted to a charismatic authority figure (like a guru). It refers to the level of intensity to which people become focused on, or attracted to, a guru, beyond anything else; which relate to spiritual bypassing and pathological altruism. The harder someone is attached to a guru, the stronger, we can say, the prescription of their guru goggles, is.

The prescription of his "guru goggles" is too strong. He can't see that the guy is a really bad. No matter what you say, he won't change his mind.