Most snakes don't have great vision to begin with- many use vision mostly to go after motion, but not to actually identify things like prey...for that, they use scent &
touch. Some snakes selectively bred for fancy colors (etc) might in fact have inherited worse vision, it's entirely possible your snake has worse vision than others.
BPs are nocturnal about hunting anyway...and as far as I know, none of them carry flashlights. We aren't seeing your snake's behavior, so you might also be mis-
interpreting your snake's intentions. Your snake's photo doesn't give any clues about your snake's vision, sorry. As noted, a vet might be able to tell you more.