Synonyms for Sleepless (same or very similar meaning)
WordNet sense 1 (experiencing or accompanied by sleeplessness):
insomniac, watchfulWordNet sense 2 (not in a state of sleep; completely conscious):
awakeWordNet sense 3 (without having the eyes closed or covered by the eyelids):
lidlessWordNet sense 4 (very attentive or observant):
alertFrom the ODE community, based on WordNetadd/edit