We demonstrate the importance of a comprehensive modeling of the dynamics of excited states in organic optoelectronics devices. Our numerical analysis demonstrates that exciton distributions extracted from spectral emission measurements of OLEDs are equivalent to those obtained by solving charge and exciton transport equations when the position-dependent coupling to optical modes is taken into account. The transport simulations are based on the extended Gaussian disorder model for organic semiconductors. Further, we show that the same numerical modeling framework can be used to accurately simulate bulk-heterojunction organic solar cells with dissociation of charge-transfer excitons. The simulations are compared to experimental data.