Insect eyes and vision

I've just added a huge chunk to this section as well as this diagram of a couple of omatidia of a compound eye. I am always getting eye questions, so perhaps this will provide some answers.

I'd much rather be out in my garden which is looking forlorn and neglected, but it is still below zero, and it is such a miserable cloudy day, that I tell myself that I'm better off in front of the log fire. Even though it is below zero the witch hazel is blooming. Its tiny yellow petals really do brighten up the grey day.