In an ocular TED-Ed lesson written by Thomas W. Cronin and animated by Josefina Preumayr and Jasmine Lister, narrator Addison Anderson explains which animals have the best eyesight for specific purposes to best suit their specific needs. These optical features exist across the whole of the animal kingdom, from the massive colossal squid to the smallest insect, from a reindeer to a butterfly, and from a peregrine falcon to a tiny goldfish. This also explains why cats have vertical pupils.
Each category has different top contenders because vision requires tradeoffs. So, some eyes are highly specialized, while others, like ours, perform decently in many categories. From eyes the size of soccer balls to those that see in UV— the ways of looking at the world are as varied as the life forms in it.