View-limiting device

In aviation training, a view-limiting device simulates instrument meteorological conditions (IMC) by restricting a pilot's field of view only to the flight instruments. They are worn by pilots who are working toward an instrument rating, which allows a pilot to fly under instrument flight rules in conditions that do not permit visual flight. They are also used by instrument-rated pilots while practicing instrument flight to maintain competency.[1][2]

Examples include foggles and the IFR hood. Foggles are glasses that have been frosted on the top half of the lenses to simulate foggy conditions.