Adjectives

(s)insomniac, sleepless, watchfulexperiencing or accompanied by sleeplessness“insomniac old people”, “insomniac nights”, “lay sleepless all night”, “twenty watchful, weary, tedious nights” (Shakespeare)
(s)lidless, sleeplessalways watchful“to an eye like mine, a lidless watcher of the public weal” (Alfred Tennyson)