US Patent 7204253 Punctum plug

A punctum plug includes a body portion having a nose and rim portions which meet at an angle which facilitates both insertion and retention. In addition, the shaft of the plug includes a circumferential groove level with the top of the body which increases flexibility between the shaft and body of the plug. Furthermore, the groove locates the pivot point of the rim of the body radially inward which increases the flexibility of the rim.