Low Angle Ring Illumination Stereomicroscopy (LARIS): An improved imaging method of Drosophila compound eyes

The compound eyes of Drosophila are widely used to gain valuable insights into genetics, developmental biology, cell biology, disease biology, and gene regulation. Various parameters, such as eye size, pigmentation loss, formation of necrotic patches, and disorientation, fusion or disruption of ommatidial arrays are commonly assessed to evaluate eye development and degeneration. In this study, we developed an improved optical alignment imaging technique named “Low Angle Ring Illumination Stereomicroscopy” (LARIS), which provides high-contrast images of the Drosophila compound eye. By capturing images of the same eye using different optical alignments of the stereomicroscope, we achieved the highest resolution with minimal reflection through the LARIS method. The images captured using LARIS clearly show ommatidial fusion, disorientation, and pigmentation loss in the Drosophila eye compared to those obtained with conventional imaging method. We believe that LARIS will open new avenues for improved imaging of the compound eyes of Drosophila and other insects.