Complex sentence: Eye puffiness (periorbital edema, or "puffy eyes") refers to the appearance of swelling in the tissues around the eyes (orbits) brought about by fluid buildup (edema).
Split into simpler sentences: Eye puffiness (periorbital edema, or "puffy eyes") refers to the appearance of swelling in the tissues around the eyes (orbits). This condition is often brought about by fluid buildup (edema).