During eye development, cell death interplays dynamically with events of differentiation to achieve the remarkably patterned structure of the fly compound eye. Mutations in genes that affect the normal developmental process can lead to excessive death of progenitor cells, or, alternatively, to the differentiation of supernumerary neurons, pigment and cone cells due to survival of cells that would normally be eliminated. These data reveal that eye development contains cell selection processes: only certain cells are selected to undergo differentiation, and supernumerary cells are actively eliminated by cell death pathways to achieve the highly ordered lattice of the eye. The final number of cells that comprise the eye is controlled through a balance of cell proliferation with proper cell differentiation and removal by cell death.