This paper examines the concept of teacher vision, showing how vision serves as a means for teachers to guide and measure their work. It discusses how teachers' passionate commitments do not divert them from their work but rather direct and shape their thinking and planning and their learning about their work. The paper also shows how vision, in the teaching context, may result in both positive and negative outcomes for teachers' emotions and learning. Information comes from a survey of 80 teachers from two teacher education programs and interviews with 16 teachers selected from the 80 who had relatively well-articulated visions. The first section describes the character of teacher vision, sharing three dimensions that help describe and analyze teacher vision. It also includes an example of one teacher's vision and shows how the dimensions can be used to characterize his vision. The second section explores the role vision plays in teachers' lives, offering a set of clusters or "constellations" of dimensions of vision associated with varying roles in teachers' lives and with a range of positive and negative emotional experiences. The final section discusses the implications of the conception of vision for teachers' learning and motivation. (Contains 21 references.) (SM)