Small rdx^unspecified eye clones lack ommatidial bristles, but produce adult eyes with otherwise normal external morphology. In eyes that mostly comprise rdx^unspecified mutant cells, the ommatidia are uneven in size, misaligned and often lack or duplicate ommatidial bristles. Morphogenetic furrow movement, photoreceptor and cone cell specification are normal in these rdx^unspecified mutant eyes. Sections through mutant ommatidia reveal the correct number of photoreceptors, but the photoreceptor clusters are loose, imperfectly aligned and irregularly spaced.