A simulated eye capable of being changed between a normal and a dilated state. The simulated eye includes a simulated pupil, a circuit board, and at least one cylindrical portion. The circuit board is configured for supplying the at least one cylindrical portion with power. The at least one cylindrical portion is electrically connected to the circuit board. When the circuit board is operated to power on or power off the at least one cylindrical portion, the at least one cylindrical portion is driven to move toward or away from the eyeball, such that a size of a colored area consisting of the simulated pupil is changed between a normal state and a dilated state.