Stylophthalmus is a stalk-eyed larva of idiacanths, rare inhabitants of the sea water column, characterized by fan-shaped pectoral fins, absence of pelvic fins and large black eyes, which sit on long thin stalks, contribute to the floating of the larva in the water column. As it grows, the eyes gradually approach the head of the fish and finally sit on it, assuming a normal position.

"Eye-footed" is the name used for fishes with eyes located on periscopic legs, which are known in some cases to be almost one-third of the animal's body length. All species of this genus are larvae of fishes already named from the orders Stomiformes and Myctophiformes, which have developed this feature as a result of convergent evolution.