Each circle
I used to stare at whole screen when I played with a mouse. might have had something to do with not having absolute positioning
Just in case anyone wanted know, rrtyui looks at whole screen (notes, cursor and followpoints), niko stares at each circle, Cookiezi stares at the cursor (though that's info from wayyyy back in 2011) and thelewa stares at patterns (he might have changed that). Don't take it for granted though, it's just things I've read from ask.fm's and what-not...
idk about other top skilled players but it would be nice to know