注目 is a verb-object compound (离合词) meaning to fix one's gaze on someone or something with attention. As a separable verb, the two syllables can be split: you can insert 了, 过, or other elements between 注 and 目 (e.g., 注过目 'have taken a look at'). It also appears in the military term 注目礼 (salute with eyes) and the common set phrase 引人注目 (to attract attention).