This paper discusses the characteristics of glasses developed in Russia for fiber optics in comparison with certain foreign glasses and evaluates the possibility of using them to fabricate illuminator fiber bundles with a nominal numerical aperture between 0.54 and 0.86. It is shown that the characteristics of the fiber bundles that have been developed make it possible to use them in medical devices, in particular, in the cystoscope-75degrees and the video laparoscope-30degrees. (C) 2003 Optical Society of America.