Metsubushi

"eye closers") or gantsubushi[1] are a variety of implements and techniques that were used in feudal Japan by samurai police and other individuals to temporarily or permanently blind or disorient an opponent.

One type of metsubushi was used by police for blowing powdered pepper or dust into the eyes of a suspect.

It is described as being a lacquer or brass box with a wide mouthpiece for blowing on, and a hole or pipe on the other end for directing the powder into the eyes of the person being captured.

[1] One type of metsubushi powder was made up of ashes, ground-up pepper, mud, flour, and dirt.

It was kept in hollowed-out eggs (happō), bamboo tubes or other small containers.