It can be activated at will in the dungeon and highlights areas of interest.
- Stealable items gain a yellow glow.
- Interactable places like gaps and ledges have exclamation marks over them.
- Overworld shadows gain a glowing outline that depends on how threatening they are. Hardest ones gain a red outline, medium ones gain a yellow one and the least dangerous encounters glow with a blue color.
In the real world, Third Eye can be used to examine on-screen locations that can be used for daily activities (NPCs, shops, confidants and Velvet Room locations).
Reading certain books also allows the protagonist to use Third Eye during certain activities. In the Batting Cages, Third Eye causes time to slow from his perspective, letting the player line up a better-timed shot. At the Fishing Pond, the Third Eye highlights fish, with different breeds glowing in different colors, allowing the player to gun for specific ones like the Guardian.
The Third Eye also helps with certain obstacles in palaces. Such obstacles are Madarame's Lasers and Sae's Dark Maze.