Following Nye & Hajnal, we explore the geometry of complex vector waves by
regarding them as a field of polarization ellipses. Singularities of this f
ield are the C lines and L lines, where the polarization is purely circular
and purely linear, respectively. The singularities can be reinterpreted as
loci of photon spin 1 (C lines) and 0 (L lines). For Gaussian random super
positions of plane waves equidistributed in direction but with an arbitrary
frequency spectrum, we calculate the density (length per unit volume) of C
and L lines.