It has been found out that currently used method of fitting celestial radio sources, using insufficient number of the reference radio sources, very often leads to the wrong fitting of certain areas of the radio sky and to the wrong optical identifications. It has been suggested to use the method of fitting radio sky directly to the optical astrometrical coordinate system, which considerably increases the number of the radio sources identifed with optical objects. In course of fulfillment of optical identifications, there was discovered a radio refraction in the interstellar and intergalactic environments with a statistical average value of ±3' at the right ascension and declination for the Galactic latitude of b>20°. The refraction must be taken into account in fulfillment of optical identifications.