Virgin eyes are often referred to when an unfortunate soul has just born witness to an abomination of all that is good and holy. It is often uttered with a sizable amount of emphasis, such as "Oh, my virgin eyes!", or "My virgin eyes hath been soiled!". Situations in which it would be appropriate to utter the phrase include, but are not limited to:

'Virgin' can also be used in conjunction with ears, and less commonly, noses and tongues.

Of course, people are always talking about how their sensory organs are so pure and uncorrupted, but it ought to be a no-brainer: I've not yet met someone whos eyes aren't virgin (in the most literal sense of the word; let that sink in for a second). If I ever did, though, I doubt anything could more fully express my shock and revulsion than exclaiming the catch phrase myself.