A review of gravity induced effects on light, both in closed circuite and in linear cavities, will be presented. The typical Lense-Thirring effect is manifested in ring lasers either as an interference phenomenon or as a beat frequency due to an asymmetry in the propagation. Gravity induces also polarization effects in linear cavities, depending on the orientation of the cavity with respect to the rotation axis of the gravity source. Finally the rotation is expected to produce also asymmetric geometrical effects (asymmetrìc ray bending)