Apparatus and methods according to which a simulated eye includes a simulated iris and a simulated pupil. An iris optical sensor is positioned behind the simulated eye and adapted to: sense a condition of light passing through the simulated pupil; and send, based on the sensed light condition, a first electrical signal. An iris motor is mechanically coupled to the simulated iris and adapted to: receive a second electrical signal; and change, based on the received second electrical signal, a size of the simulated iris. In some embodiments, an iris size sensor is adapted to: sense the size of the simulated iris; and send, based on the sensed size of the simulated iris, a third electrical signal. The second electrical signal may include or be based on the first electrical signal, the second electrical signal, or both.