I CAN NOT play a guitar with a capo. My brain is SO LOCKED on those fret markers and chords in positions related to those markers that I just can't use a capo.
You need to stop looking at the fret board. Play by feel. You should know the chords and be able to jump to them instantly. So, don't look. Only look if you need to jump to a barre chord or to fond the first note of a solo.... then simply do a quick mental calculation.... capo is up 2 frets (for example) so the barre is up 2 frets past the marker.
Once I get into a solo or chords on a song, I rarely look at the guitar fret board. How else can one sing and play at the same time?