1
general::
Phrase(s): in a fog [and] in a haze
Fig. dazed; not paying attention to what is going on around one; not alert. • Jane always seems to be in a fog. • When I get up, I’m in a fog for an hour. • After surgery, I was in a haze until the anesthetic wore off.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Also, in a haze. Preoccupied, not paying attention; also, at a loss, confused. For example, After the accident he went about in a fog, even though he had not been injured, or Millie always seems to be in a haze; she never knows what's going on. These expressions allude to fog or haze obscuring one's view; the fog usage dates from about 1600, haze from about 1800.
American Heritage Idioms