A relative of modern monitor lizards, Saniwa ensidens which lived 50 million years ago in North America, had four eyes. It is the only known jawed vertebrate with four eyes. Rather unspectacularly, the extra two eyes are the pineal and parapineal organs (amongst living reptiles, the Tuatara and several lizards have a visible pineal organ in at least some stages of life).
Here is a press article: This ancient lizard may have watched the world through four eyes
Here is the actual scientific paper: http://www.cell.com/current-biology/fulltext/S0960-9822(18)30206-9
And here is my recreation of a lizard with four eyes: Liiiizard.
Here is a press article: This ancient lizard may have watched the world through four eyes
Here is the actual scientific paper: http://www.cell.com/current-biology/fulltext/S0960-9822(18)30206-9
And here is my recreation of a lizard with four eyes: Liiiizard.