About 63% of ommatidia in argos^Δ7/argos^A254Δ15 animals exhibit extra R cells. Of those that ommatidia that remain about 47% exhibit misrotations, about 10% exhibit achirality, and about 4% exhibit the wrong chirality.

Homozygous mutants show two or three bracts per mechanosensory bristle, clustered on its proximal side.

Retina has a rough surface and lenses are fused to a giant lens. Most ommatidia contain additional photoreceptor cells. Additional cells are recruited from the eye disc epithelium that are normally destined to die. Rhabdomeres are malformed. Defect in photoreceptor axon guidance causing an aberrant projection pattern of axons. Heat induced expression of argos^hs.PF throughout larval and pupal development almost completely suppresses the mutant phenotype; nearly all ommatidia contain a normal number of retinula cells and photoreceptor axon guidance is normal.

Homozygous viable. In the posterior region of the eye the lenses of many ommatidia fuse to build one giant lens. Each ommatidium has an increased number of cone cells, 7-10 compared to 4 in wild type eyes. Axons that grow through the optic stalk into the larval brain stall on entry into the larval brain hemisphere and show an aberrant projection pattern.

Exhibit argos rough eye phenotype (due to additional photoreceptors) and fused lens phenotype in the posterior eye. Photoreceptor axons project through the optic stalk into the lamina presumptive area but fail to penetrate into deeper layers of the developing optic lobe. The optic lobe shows variable degrees of disorganisation, defects can be detected in the lamina, medulla and lobula complex.