Infected Vision is a type of sensory power obtained by Alex Mercer. It allows him to see the world as the Infected see it and tune into the Hive Mind itself. Alex uses this ability to spot enemies at range, and pick out hostile entities from simple bystanders. This sense reduces most sound, and dulls visual details to enable Alex to highlight and pick out every potential target from a given environment in the city. It highlights all military and infected with an orange-white glow, while reducing everything else to a dull red.
Once Alex consumes the DNA of the first Leader Hunter, Alex starts to tap into the Hive Mind. It enables him to see Carriers -- those who have unknowingly been infected with the Blacklight virus and haven't yet begun to develop any symptoms. Connectivity increases with each Carrier consumed, but slowly drains over time. Once Alex establishes a clear connection, the full power of Infected Vision is unlocked. Alex uses this ability to track down the Leader Hunter who took Dana.