Getting the bees eye view

Getting the bee`s eye view

What is it like to see as a bee? By understanding vision at the retinal, cortical, and computational levels, Andrew Giger at the Centre for Visual Sciences at the Australian National University (Canberra, Australia) hopes to understand more about visual perception, especially in biological systems that have very little processing power. To aid in his research of training and testing bees, Giger has developed B-Eye, software that simulates the optics of a honey bee`s eye. Based on a number of anatomical and behavioral studies, the program`s input consists of a gray-scale image of the pattern the model bee is looking at and a set of parameters determining the bee`s position, the dimension of the pattern, and the output.

Bees, like most other insects, have hemispherical compound eyes--arrays of hundreds of single eyes, each with their own lens and each looking in a different direction. B-Eye`s first step is to project a flat-field image onto a bee`s hemispherical frontal visual field. To understand how a bee sees, an array of single eyes (simulating the compound eye) is modeled. Using this model, the computer program can generate images depicting gray-levels that each single eye within the compound eye would see.

"In reality, the single eyes of a bee`s compound eye are arranged in a hexagonal array," says Giger. "But because each single eye looks in directions that are not necessarily radial with respect to the bee`s head, the array must be displayed at the level of the retina. Thus, the image must be displayed as it appears on the eye`s surface, as a hexagonal array of patches, where each patch corresponds to one single eye within the compound eye."