A cool CGI reconstruction of Cambrian-era creatures found fossilized at the Burgess Shale:
The two large swimming predators are Hurdia and its cousin Anomalocaris-- the latter of which had very sharp eyes:
The fossils represent compound eyes -- the multi-faceted variety seen in arthropods such as flies, crabs and kin -- and are amongst the largest to have ever existed, with each eye up to 3 cm in length and containing over 16,000 lenses.
The number of lenses and other aspects of their optical design suggest that Anomalocaris would have seen its world with exceptional clarity whilst hunting in well-lit waters. Only a few arthropods, such as modern predatory dragonflies, have similar resolution.
The existence of highly sophisticated, visual hunters within Cambrian communities would have accelerated the predator-prey 'arms race' that began during this important phase in early animal evolution over half a billion years ago