The Drosophila (fruit fly) eye has been the subject of extensive research, ranging from mutations that cause eye discolorations to the fascinating compound structure, which is built into a formation of 800 individual eyes termed ommatidia. The digital image presented below features a double-labeled fluorescence image of an imaginal disc from the Drosophila second larval instar development stage.

Fruit Fly Imaginal Disc: Eye (High Magnification) Specimen: Drosophila Imaginal Disc Technique: Fluorescence (Double Label)

Ommatidia each have their own miniature lens system, which operate in a somewhat independent manner. At the core of each eye are eight specialized, light-sensitive neurons (R-cells) and four non-neuronal cells. Surprisingly, scientists have found that introducing the fruit fly's eyeless gene into other parts of the organism's anatomy, such as on the wings or legs, results in the formation of numerous eyes in those areas.