  Phase singularities are dislocations widely studied in optical fields as well
as in other areas of physics. With experiment and theory we show that the
vectorial nature of light affects the spatial distribution of phase
singularities in random light fields. While in scalar random waves phase
singularities exhibit spatial distributions reminiscent of particles in
isotropic liquids, in vector fields their distribution for the different vector
components becomes anisotropic due to the direct relation between propagation
and field direction. By incorporating this relation in the theory for scalar
fields by Berry and Dennis [Proc. R. Soc. A 456, 2059 (2000)], we
quantitatively describe our experiments.
