  Only one optical flash associated with a gamma-ray burst has been detected so
far by ROTSE. There are also upper limits obtained by several groups for
several bursts. Recent model calculations indicate a possibility that optical
flash may precede the main GRB. Such flashes are undetectable in the currently
popular observing mode, with optical instruments responding to GRB triggers.
There is a need to develop all sky optical monitoring system capable of
recognizing flashes in real time, and more powerful instruments that could
respond robotically to optical triggers and carry out follow up observations.
