What does Illuminate Symbol Mean?

I love triangle, But I dislike the symbol Illuminate. I dunno why... I don't like the single eye in center of triangle.I don't know what does it mean. I don't know why people usually choose that symbol as display picture on bbm or... Post that symbol on Instagram. Could u please tell me about them? I don't why it so popular now in teen life? Is that controversial? O my god...