Variable iris using charged opaque particles The present invention relates to a variable iris using charged opaque particles, and to a method for operating such a variable iris.According to the invention, the variable iris has a first transparent substrate and a second transparent substrate, which are separated by one or more ribs to form a cell confining charged opaque particles, the first transparent substrate being provided with at least a first electrode and a second electrode both being adapted to be connected to a voltage source for acting on the charged opaque particles, and at least a third electrode adapted to be connected to the voltage source for acting on the charged opaque particles, the voltages applied to the first electrode, the second electrode, and the third electrode being controllable to have the same or opposite signs. The variable iris further has a pulse driver for applying voltage pulses to the electrodes.