In the eyes of rap^x-3 mutant adults, there is an increase in the number of pigment cells, resulting in a rough eye phenotype, with disordered ommatidia and eye bristles. Investigation into the cause of this phenotype shows that cells posterior to the morphogenetic furrow in the third larval instar disc do not exit the mitotic cycle at the appropriate time and initiate additional abnormal cell cycles. Cells within the morphogenetic furrow also fail to arrest in G1 at the appropriate time.

Eyes have a rough exterior surface due to the uneven size and shape of the ommatidia. R7 cell is abnormally differentiated and often missing. R2, R5 and R8 cells are formed but their precise positioning and arrangement is disturbed. R3 and R4 differentiate properly, R1 and R6 fail to be recruited into the pattern of the developing eye. Ommatidia exhibit variable number, position and size of the R cells. Increase in cell death posterior to the morphogenetic furrow.