If the blinding rogue was heavy Subtlety (i.e. has speced "Heightened Senses"), he probably had improved stealth detection and perhaps that allowed him to follow you. I have a 70 rogue speced for this and can usually spot another rogue stealthing about and get a sap in on em. That said my Vanish is busted for me ~half the time, usually with hunter pets but I've been dotted etc. as well.

And Fireflash38 is technically correct, but Vanish is improved stealth. You enter a higher "state" of stealth for a few seconds, or at least you are supposed to, then return to normal stealth after it wears off. So in theory it should be much harder to detect a recently vanished rogue vs. a regularly stealth rogue.


FYI this is from the worldofwarcraft.com encyclopedia about Vanish:

"Allows the Rogue to vanish from sight, entering an improved Stealth mode, but reducing the speed to X% of normal for Y seconds. Spellcasting against a Rogue that successfully uses Vanish will now be interrupted. Vanish breaks root and snare effects. Vanish cancels spells in progress and missiles in flight if they are being cast at the vanished player. If a DoT is active when you use Vanish, unless it is a snare as well, it will remain and break Vanish the next time it does damage. Vanish removes effects that allow the caster to always remain aware of their target (currently Hunter's Mark and Mind Vision)."