Sight may well have been the driving force behind the Cambrian explosion, when the first animals leapt into the fossil record about 550 million years ago. Thanks to a series of surprises in molecular biology, we now know how eyes evolved in great detail. Lens proteins and crystals were recruited from an astonishing range of sources, from calcite to mitochondria to stress proteins, but the ubiquitous light-sensitive protein rhodopsin probably evolved in algae, where it is used to calibrate light levels in photosynthesis.
With evolution it is all so easy. So easy that anyone can contrive their own narrative. I have seen several such explanations for the Cambrian explosion. This wide variety of ideas indicates the lack of an explanation that is scientifically compelling. Nonetheless, evolutionists such as Lane claim detailed knowledge of how marvels such as vision evolved, though they have nothing of the sort.