Multi-layer polarizing panels are a technology that has been proposed for improving lighting quality in interior environments. Different authors have examined a variety of different conditions, have used different performance models in their evaluation of the potential of this technology, and have come to markedly different conclusions. This paper discusses how variations in conditions and performance models affect the evaluation of the performance potential of polarized lighting systems. The importance of the light source-task-eye geometry, which determines the benefit that can be achieved with polarizing luminaires, is discussed in detail.