In common with most other insects the bumblebee compound eye is formed of a large number of individual hexagonal units called ommatidia. The outside part that we can see is called the lens, this lies over the crystalline cone, and beneath this are the visual cells leading to a nerve axon and the brain. There are three types of visual cells, ultraviolet-sensitive, blue-sensitive and green-sensitive. The ommatidia do not have any focusing ability.
Bumblebees, again in common with many other insects, also have three ocelli (often called primitive eyes) arranged in a triangular pattern on the top of the head, see the photographs above, below and on the right. Ocelli look like shiny bumps, and resemble the 2 large “headlamp” type eyes. The ocelli detect changes in light intensity. (Bumblebee.org)
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