This is a project that consists of a compilation of educative optical simulations with the goal of illustrating the concept of spatial coherence. The simulations focus on visualizing the differences between the behavior of incoherent and coherent light propagation through different time scales: femtoseconds, picoseconds, and microseconds. When the time scale goes up and the field is averaged, the interferometric visibility of the fringes disappears, yielding a uniform distribution. The finite-difference time-domain (FDTD) simulations reproduce the results of the Van-Cittert-Zernike theorem, showing how the interferometric visibility of the fringes varies due to the different parameters of the simulation.