The halibut is born like a normal fish, with two eyes placed in the normal spots. He then falls over to one side and the eyes move to the top of his body, making both eyes on the dark side.
We catch halibut on the bottom of the sea. They are 20 to 200 lbs. The bottom of the fish turns white and the top of the fish turns dark. When there is a predator under him, he blends in with the sand on the bottom of the sea. When there is a predator above him, he blends into the sea above him.
Notice this halibut's eyes. You can see his second eye on the top of his head.