Mosquito eye. Coloured scanning electron micrograph (SEM) of a mosquito eye. The compound eyes are made up of many hundreds of lenses called ommatidia. Every individual ommatidium that make up the thousands has its own cornea, lens and photoreceptor cells that distinguish colour and brightness. The individual ommatidia channels light through a lens, down a cone and then down a channel called rhabdom. The rhabdom consists of light sensing cells. The rhabdom are intern connected to optical nerve cells that produce the image. With all the ommatidia piled next to one another, a bulge is created resulting in a very wide view. Every ommatidia is set at a slightly different angle creating a mosaic like view that has poor quality but is very good for picking out any movement. Magnification: x 3000 when printed 10cm wide.