If a person had an image appear for a moment after waking up or if they see something in the dark it is not considered a dream because they were awake when it occurred.
ɪf ɐ pˈɜːsən hæd ɐn ˈɪmɪdʒ ɐpˈɪɹ fɚɹə mˈoʊmənt ˈæftɚ wˈeɪkɪŋ ˌʌp ɔːɹ ɪf ðeɪ sˈiː sˈʌmθɪŋ ɪnðə dˈɑːɹk ɪɾ ɪz nˌɑːt kənsˈɪdɚd ɐ dɹˈiːm bɪkˈʌz ðeɪ wɜːɹ ɐwˈeɪk wɛn ɪɾ əkˈɜːd.