We present the results of B, V, and R(c) surface photometry of UGC 7576 and UGC 9796 - two well-known polar-ring galaxies (PRGs). Comparison with other kinematically confirmed PRGs with S0 central galaxies yields the following principal results. The PRGs central bodies have the absolute luminosities and colours of normal S0 galaxies; exponential disks of PRGs are significantly brighter and shorter in comparison with the disks of normal SO galaxies; polar rings have total luminosities and HI mass-to-B luminosity ratios corresponding to normal late-type spiral galaxies; there is an evidence of roughly normal (as in Milky Way) gas-to-dust ratio for rings; there is an active star formation in the polar rings. These results support the standard scenario of PRGs formation as a consequence of galaxy-galaxy interactions.