Invisibility - Sight While Invisible

Sight While Invisible

One of the few fictional examples of a double-blind cloak comes from the Thrawn Trilogy of Star Wars novels. Grand Admiral Thrawn's cloaking devices make the ships wielding them invisible, but also prevent those inside the ship from seeing out. Thus, most of the time, ships using this type of cloak remain stationary, dropping the cloak just before battle. (See the beginning of Specter of the Past for an example of this tactic.) An earlier example can be found in the Traveller role-playing game, in which starships equipped with black globe generators are afforded resistance to physical detection and attack at the cost of being blind. The generators are set to 'flicker' at a pre-set frequency, permitting the ship's sensors to penetrate the globe but at the cost of momentary vulnerability.

In the Halo video game series, the "active camouflage" power-up renders the wearer only partially invisible — the visible silhouette of the wearer is likely necessary so that the wearer's retinas can absorb what little light they need to see (though it also exists for game balance reasons). In the video game Quake, picking up a magic ring turns the player invisible to monsters for thirty seconds. In multiplayer deathmatch mode, only the player's eyes are visible, giving his opponents only a small clue to his location. With eyes being visible, light can be absorbed and the player can see.

In the Predator series, the Predator's cloaking device is similar to the active camouflage featured in Halo. The Predator can still "just" be seen by the careful observer. Whether this is to allow some of the EM spectrum to reach the Predator's eyes is debatable as the Predator sees in infrared. In fact theoretically the cloaking system could be manufactured to completely bend all visible light around it leaving him 100% invisible to species that only perceive visible light. However, this also may be the result of the species keeping a fair advantage, as Predators are known to be honorable warriors.

In The Invisible Man, the main character of Darien Fawkes turns invisible thanks to a chemical called quicksilver that causes him to reflect light in a frequency that the human visual cortex cannot process. On some occasions, Darien has been able to see in this spectrum by turning his eyes invisible, allowing him to see other invisible people; when he was once blinded, he was able to use this ability to allow himself to see while his eyes healed to serve as a substitute visual cortex.