Elixir of the Searching Eye

Stealth Detection
as of patch 2.1

5 points of stealth detection raises your stealth detection by 1 level. So a level 70 player with 10 points of stealth detection can see stealthed targets as if he were a level 72 player.

Stealth works the same way. 5 points of stealth raises your effective stealth by 1 level. Rogues and druids can both spend talent points to get 15 points of increased stealth, raising their effective stealth by 3 levels.

***** ABILITIES AND TALENTS *****

ROGUE
Talent - Heightened Senses http://www.wowhead.com/?spell=30895
Rank 1: +3 stealth detection
Rank 2: +6 stealth detection

WARLOCK
Ability - Felhunter's Paranoia http://www.wowhead.com/?spell=19480
+30 stealth detection . . . (party buff aura with 30 yard radius around pet)

HUNTER
Ability - Track Hidden http://www.wowhead.com/?spell=19885
+30 stealth detection

HUMAN
Racial Ability - Perception http://www.wowhead.com/?spell=20600
(lasts 20 seconds, 3 minute cooldown)
+50 stealth detection

***** WORN ITEMS *****

Engineering level 350 goggles http://www.wowhead.com/?spell=40273
(there are 11 versions of these goggles, all are BoP)
+5 stealth detection

Bloodvine Lens http://www.wowhead.com/?item=19998
(Leather hat, Requires 300 engineering and level 60, BoE)
+10 stealth detection

The Night Watchman http://www.wowhead.com/?item=31333
(Leather hat, Requires level 70, rare BoE world drop)
+10 stealth detection

Catseye Ultra Goggles http://www.wowhead.com/?item=10501
(requires 220 engineering, BoE)
+18 stealth detection

Druid PVP Gloves (all are level 60 gloves, druid only)
Alliance: http://www.wowhead.com/?item=16448 http://www.wowhead.com/?item=23280
Horde: http://www.wowhead.com/?item=16555 http://www.wowhead.com/?item=22863
+10 stealth detection

***** Consumable Items *****

Catseye Elixir http://www.wowhead.com/?item=10592
(potion, created by alchemists, lasts 10 minutes)
+10 stealth detection

Elixir of the Searching Eye http://www.wowhead.com/?item=22830
(potion, created by alchemists, lasts 10 minutes)
+15 stealth detection

Distilled Stalker Sight http://www.wowhead.com/?item=31449
(potion, BoP quest reward, lasts 10 minutes)
+15 stealth detection

***** A special note regarding vanish *****

The most stealth detection you can achieve is to be a human rogue, grouped with a warlock who has a felhunter out, wearing Catseye Ultra Goggles, drinking an Elixir of the Searching Eye, and using your racial Perception. This will get you a total of 119 points of stealth detection. However, the effect of vanish is as follows:
. . . . . . . Rogue Ability - Vanish (enters an improved stealth mode for 10 sec)
. . . . . . . Rank 1: +170 stealth http://www.wowhead.com/?spell=11327
. . . . . . . Rank 2: +270 stealth http://www.wowhead.com/?spell=11329
. . . . . . . Rank 3: +370 stealth http://www.wowhead.com/?spell=26888
As you can see, it is not possible to have enough stealth detection to see an equal level rogue who has performed a vanish.

***** A special note regarding Invisibility and Invisibility Detection *****

Stealth is NOT invisibility and invisibility is NOT stealth.
Stealth detection will NOT help you see invisible targets.
Invisibility detection will NOT help you see stealthed targets.

Lesser Invisibility Potion http://www.wowhead.com/?item=3823
+100 Invisibility

Invisibility Potion http://www.wowhead.com/?item=9172
+200 Invisibility

Elixir of Detect Lesser Invisibility http://www.wowhead.com/?item=3828
+100 to Invisibility Detection

Warlock spell, Detect Invisibility http://www.wowhead.com/?spell=132
+1000 to Invisibility Detection

For anybody who hasn't learned this by now

Stealth & Invisibility are two completely DIFFERENT things. Both have the same intent of hiding from enemy players/npcs, but the simliarity stops there.

1. 
   
2. Stealth is essentially a fading - only becoming visible when an opponent is close enough to the stealth target and dependent on modifiers such as NPC/Player Level, detection potions, etc. and direction
3. 
   
4. Invisibility is more like a phasing of the user, similar to phasing in regions for quests. Would-be attackers are unable to see an invisible targets unless they have a "Detect Invisible" mechanic or the target walks into a hunter flare.
5. 
   

• 
  
• Using detect invisible will not allow you to see stealthed targets.
• 
  
• Using stealth detection mechanics (e.g. catseye elixir) will not allow you to see an invisible target.
• 
  
• Hunter Flares will reveal both.
• 
  

NPC guards with an eyeball above them as viewed while stealthed or invisible can see BOTH.

Though it's classified as an elixir, it won't use up either your Guardian or Battle slot. Thus, you can use it with a flask or the combination of a battle and guardian elixir. However, it will not stack with Catseye Elixir. Searching Eye is the more powerful effect, so it won't let you drink Catseye while it's still active.