Invisibility is a limited form of Illusion, where the possessor can affect the visual cortex of anyone so that the possessor cannot be seen. Those who possess this specific ability are immune to this effect from others, and thus can see others with the same ability even when this ability is active. It is unknown if those with more general illusion abilities are also immune.
While this ability gives the possessor a considerable stealth advantage, the ability does not suppress sound, so the possessor must make special effort to be quiet while using their ability. Invisibility also does not appear to render the possessor immune to infrared detection. Possessors must also be aware of other secondary effects they have on the environment (footprints; opening or closing doors) which may also render them susceptible to detection. Another form of invisibility displayed throughout the series is Teddy's cloaking powers, this ability allows him to make other objects invisible.