This paper responds to the burgeoning literature on mathematics teacher noticing, arguing that its cognitive orientation misses the cultural and ideological dimensions of what and how teachers notice. The author highlights Goodwin's concept of "professional vision" as a way of bringing analyses of culture and power into studies of teacher noticing. The case of a high school algebra teacher who learned to notice the mathematical strengths of students from marginalized groups is used to illustrate how this might be done. The teacher's noticing involved not only cognitive processes like attending to, interpreting, and deciding how to respond to students' thinking, but also managing dominant ideologies that position students--especially students from non-dominant communities--as mathematically deficient rather than as sense-makers whose ideas should form the basis for further learning. The paper advances the field's capacity for understanding the challenges that teachers face as they attempt to notice in ways that are ambitious as well as equitable.