Surefire tactical flashlight effective on sunglasses?

Question

I hear those super bright flashlights can blind the assailant for a few seconds, but how effective is such a flashlight if the assailant were wearing sunglasses?

Answer 1

The most recent reference I've found, from 2007, indicates that tinted sunglasses may indeed block the effect, although it seems like the disorientation effect may still be effective.