This slide shows a stained cross section of an insect eye. The compound eye of insects (and other arthropods) is composed of many (up to thousands) of individual photoreceptor units called ommatidia.  Each eye is covered by a transparent portion of the cuticle called the cornea (pointed to by the blue arrow). An insect such as a honeybee can see simultaneously in almost all directions, but accommodation is limited and only more distant objects will be in clear focus.