Gravitational lenses and decay of dark matter

The possibility that gravitational lenses are actually typical galaxies and clusters which have changed significantly during recent cosmological times is explored. Consideration is also given to the possibility that at z = 1, the galaxies and clusters were more compact and had higher velocity dispersions. These galaxies could produce the seven observed lensed systems while these clusters could produce splittings as large as 157 arcmin. 27 references.