The Cape Skimmer dragonfly is a common dragonfly endemic to the Western Cape and southern parts of the Eastern Cape in South Africa. 
It frequents open waters like rivers, streams, marshes, and ponds.
A mature male has striking, dark turquoise-blue compound eyes. 
Each eye contains up to 30,000 individual lenses.
providing the dragonfly with almost a 360 degree field of vision. 
In addition to the main compound eyes it also has three tiny simple eyes that act as orientation sensors.
That sort of eyesight makes the Cape Skimmer an excellent ambush hunter. 
They sit quietly to spot passing insects and then zip out to catch them
and then fly right back to the same perch to rest and wait for the next passing meal to fly by.
They are cold-blooded insects and use the sun to warm up their flight muscles. 

More information from iNaturalist