Why do dragon and damselflies have such big eyes?

Entomologist Richard Jones answers your wild question.

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These ferocious aerobatic hunters are renowned for their enormous compound eyes, which give them the optical acuity necessary to seize prey in mid-air over open water. Both dragons and damsels have short antennae, so vision is their primary means of navigating and capturing food.

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Their eyes are made up of thousands of ommatidia (telescope-shaped clusters of photoreceptor cells) that resemble a honeycomb. These collect light and signals that, when they are processed by the brain, can produce a clearer and less pixilated image than in other smaller-eyed insects. Some dragonflies can also see colours that we can’t, such as ultraviolet.

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While dragons’ eyes are on the front of the head, damsels’ are on the sides. This may give less frontal vision for zoom-and-swoop attack, but allows all-round – including above and behind – perception of their aerospace. This is vital for hovering insects, especially damselflies, which often travel among the herbage rather than skimming the water or flying in the open.