Owl City - Deer in the Headlights Lyrics Meaning

'Deer in the headlights' refers to the tendency of deer to remain completely still, stunned by the sudden brightness of the oncoming car.

Basically, Adam recounts how he fell in love with a girl, and how she seems to reject him (with pepper spray). He apparently 'got the sense [he] was not her type.' He then begs the girl to give some sort of 'sign' whether she likes him or not.

Throughout the chorus and in the end,
"Didn't you know love could shine this bright?"
"If love was a beam, you'd be blind in both eyes."
"Put your sunglasses on 'cause you're a deer in the headlights."

Light equals love. He tells his plan of stunning the girl with an onslaught of love, whether she accepted it or not, and that she better be prepared.