Blinds the target, causing it to wander at 40% of move speed confused for up to 10 seconds. This is a disorient effect. Any damage will cancel the Blind effect. Blind cancels combat (turns off auto attacks) when used.
Any further damage will break the effect of Blind, so Blind does not combine well with DoT attacks like Garrote or Rupture.
Elusiveness reduces the cooldown of your blind by 30/60 seconds.
Tips and tactics
When fighting rogues, spamming your blind ability can give you an opportunity to break out of a stunlock.
Blind gives opportunity to use First Aid - use it!
Blind can now be dispelled with PvP trinket so beware of relying fully on it.
Blind is a great way to interrupt a spellcast in the case of an emergency when your Kick is either on cooldown or you are too far away.
In PvP, if you find yourself in need of a Blind and have Deadly Poisons stacked on the target, use Envenom to consume the poison so you can safely Blind the foe, bandage, and restealth.
Hotfix (2009-04-30): "Blind (Rogue) is now in the same diminishing returns category as Fear effects, but no longer shares diminishing returns with Cyclone (Druid). "
Patch 2.3.0 (13-Nov-2007): Blind is now a physical (no longer a poison) attack. [Reagent] requirement removed. Now shares the same diminish category as Cyclone and is now diminished in PvE as well as PvP. Previously blind was a nature attack like poison. [Blinding Powder] is now a Grey-quality item ("vendor trash") which can sometimes be found in lockboxes obtained through Pickpocketing. There is a tooltip on the item that explains why Blind no longer needs a Reagent: "Once favored by rogues as a blinding agent, it was abandoned for more readily available resources... like dirt."