  The problem of critical behaviour of three dimensional random anisotropy
magnets, which constitute a wide class of disordered magnets is considered.
Previous results obtained in experiments, by Monte Carlo simulations and within
different theoretical approaches give evidence for a second order phase
transition for anisotropic distributions of the local anisotropy axes, while
for the case of isotropic distribution such transition is absent. This outcome
is described by renormalization group in its field theoretical variant on the
basis of the random anisotropy model. Considerable attention is paid to the
investigation of the effective critical behaviour which explains the
observation of different behaviour in the same universality class.
