Update on punctal plugs.

Punctal plugs have offered a safe and often reversible treatment for aqueous-deficient dry eye for over three decades. However, they represent only one tool in our armamentrarium to help patients with dry eyes, and plugs do have limitations. This article briefly reviews the history of occlusive treatments for aqueous tear deficiency and provides an update of recent advancements in punctal and canalicular occlusive materials and techniques.