part of establishment of planar polarity compound eye morphogenesis establishment or maintenance of cell polarity establishment of ommatidial planar polarity biological_process GO:0042067 The specification of polarized ommatidia. Ommatidia occur in two chiral forms. The trapezoidal arrangement of photoreceptors in the dorsal part of the eye is the mirror image of that in the ventral part. establishment of ommatidial polarity