Compensatory lenses: are lenses to compensate for a vision problem such as nearsightedness, farsightedness, astigmatism, and presbyopia.
Treatment lenses (performance lenses) have a therapeutic effect and are used for things like:
relieving eye strain
encouraging eye movements
providing focus change
enhancing peripheral vision
Often times these are prescribed as reading glasses or multifocal lenses. The multifocal lenses we use for children are for anti-fatigue design as compared with progressive lenses traditionally used for adults.