Hoplonemertean larvae
NOTE: It is likely that the larvae of many hoplonemerteans (e.g., Emplectonema sp. 1, Paranemertes californica, Poseidonemertes collaris, Gurjanovella littoralis, Tetrastemma bilineatum) start out with just a single pair of eyes, and possibly, develop more pairs before settlement because adult individuals often have many more eyes.
Does the larva have two pairs of eyes or one?
Larva with two pairs of eyes
Larva with one pair of eyes