Abstract: The invention contemplates a disposable surgical drape of pliable elastomeric film, precut and seamed for sterile packaging and instant readiness to assemble to a microscope head, with assurance of microscope sterility during surgical procedures. The drape is so formed as to enable simple and effective lens barrels, without requiring use of rubber bands, pressure-sensitive tape, adhesive bands or the like. A kit including one disposable drape also includes an objective-lens adapter ring which not only correctly retains drape material at the periphery of an objective-lens barrel, but also provides a rugged base, external of the drape, for ready removable mounting of successive disposable plane-parallel protective cover plates as they may become soiled in the course of any single surgical procedure.