We report the fabrication of artificial ommatidia, the imaging units of insects' compound eyes, by use of polymer integrated optics. These biomimetic structures are obtained by configuring microlenses to play dual roles for self-writing of waveguides (during the fabrication) and collection of light (during the operation). The artificial ommatidium, consisting of a microlens, a spacer, and a waveguide, directly resembles the structure of its biological counterpart. Optical characterizations reveal single-peak angular sensitivity with a +/-0.75degrees acceptance angle that is comparable to those found in nature. Using geometric and physical optics, we also investigate the relationship between angular sensitivity and the geometry of artificial ommatidia. (C) 2005 Optical Society of America.