Transverse Shifts in Paraxial Spinoptics
  The paraxial approximation of a classical spinning photon is shown to yield an "exotic particle" in the plane transverse to the propagation. The previously proposed and observed position shift between media with different refractive indices is modified when the interface is curved, and there also appears a novel, momentum [direction] shift. The laws of thin lenses are modified accordingly. 
C. Duval, P. A. Horvathy, P. M. Zhang
physics.optics cond-mat.other hep-th math-ph math.MP