Righteye flounders are a family, Pleuronectidae, of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the opposite, with their eyes on the left side. A small number of species in Pleuronectidae can also have their eyes on the left side, notably the members of the genus Platichthys. The name of the family is derived from the Greek πλευρά (pleura), meaning "rib" or "side", and νηκτόν (nekton), meaning "swimming".