PRIVATE EYE - Optical zoom length is increased while crouching.
Gain 50% increased zoom while crouched.
In Destiny, PRIVATE EYE is a Weapon Upgrade that can be found on a few precision weapons and Rocket Launchers in the game. Weapons in Destiny pull each Upgrade at random from specific pools (with a few Weapons that are an exception). This Upgrade increases your zoom by a great deal when crouched.
To see more info on exactly which Weapons this Upgrade can be found upon click the link below:
To see more about how this Weapon Upgrade fits into these pools, please click the links below:
SCOUT RIFLE WEAPON UPGRADES
SNIPER RIFLE WEAPON UPGRADES