Compound eye of the fruit fly (Drosophila melanogaster), coloured scanning electron micrograph (SEM). The eye consists of many lenses known as ommatidia (dark red) and bristles (green and blue). Each ommatidium works as a simple eye that sends a signal to the fly's brain. All signals collected from all the ommatidia are combined by the fly's brain to form a mosaic-like image. Although not able to form a sharp, well defined image, the compound eye of the fruit fly is good at detecting movement. The compound eye of the fruit fly is one of the most advanced among insects and has a very regular arrangement. This allows researchers to easily identify any defects or morphological disruptions that occur due to laboratory based genetic manipulations. Magnification: x2500 when printed at 10cm wide