wakeful in WordNet English dictionary

1. carefully observant or attentive; on the lookout for possible danger
   "a policy of open-eyed awareness"; "the vigilant eye of the town watch"; "there was a watchful dignity in the room"; "a watchful parent with a toddler in tow"
   argus-eyed  open-eyed  vigilant  wakeful 
   
2. (of sleep) easily disturbed
   "in a light doze"; "a light sleeper"; "a restless wakeful night"
   light  wakeful 
   
3. marked by full consciousness or alertness
   "worked every moment of my waking hours"
   waking  wakeful