Since insects have compound eyes (with straight tubes or light guides radiating out from the centre of the eye like the spines of a hedgehog), this might amount in practice to something as simple as keeping the light in one particular tube or ommatidium.    From Wordnik.com.  [The God Delusion]

In the honeybee each ommatidium contains six green photoreceptors, which give rise to the short visual fibres.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Each of the crab's ommatidium is like one of your camera's pixels - but instead of millions there is just 8,000.    From Wordnik.com.  [Latest News - Yahoo!7 News] Reference

In Bombus impatiens a similar pattern is likely, since UV opsin is found in zero, one or two receptors per ommatidium, and these cells always correspond to the R1 or R5 photoreceptors.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference