Light scattering techniques have been used to study the phase separation of a sheared binary fluid of nitrobenzene and n-hexane at critical composition. Shear was seen to prevent the development of decomposition. The system is quenched when the shear is removed, allowing anisotropic spinodal decomposition rings to appear. When a periodic (frequency Ω) shear was applied, a permanent anisotropic ring pattern was formed. The radius of the ring, in units of the correlation length, exhibits a scaled behaviour versus Ω-1 or the time t after the quench, if Ω-1 or t are expressed in units of the fluctuation lifetime. Mean-field theory seems to be relevant.