**EXHIBIT 21**

**LIST OF SUBSIDIARIES OF MENTOR CORPORATION**

** **
| Subsidiary                                                                                         | State of Incorporation or Organization |
|----------------------------------------------------------------------------------------------------|----------------------------------------|
|                                                                                                    |                                        |
| Biopolymers (Scotland) Limited                                                                     | Scotland                               |
| Byron Medical, Inc.                                                                                | Arizona                                |
| Havas  Medical, B.V. (merged into Mentor Benelux     B.V. 11/17/97)                 |                                        |
| MDI  Company Ltd.                                                                                  | Bermuda                                |
| Mentor 1983 Research Limited Partnership      (dissolved 6/14/00)                   |                                        |
| Mentor  Benelux B.V.                                                                               | Netherlands                            |
| Mentor  Caribe, Inc. (Dissolved 12/31/99)                                                          | Delaware                               |
| Mentor  Deutschland GmbH                                                                           | Germany                                |
| Mentor  International Holdings Alpha, Inc.                                                         | Delaware                               |
| Mentor  International Holdings Beta, Inc.                                                          | Delaware                               |
| Mentor  International Holdings Camda, Inc.                                                         | Delaware                               |
| Mentor  International Holdings Delta, Inc.                                                         | Delaware                               |
| Mentor  International Sales Corporation                                                            | U.S.  Virgin Islands                   |
| Mentor International, EURL                                                                         | France                                 |
| Mentor International, LLC                                                                          | Delaware                               |
| Mentor Japan K.K. (dissolved)                                                                      |                                        |
| Mentor  Medical Inc.                                                                               | Delaware                               |
| Mentor Medical Italia, S.r.l.                                                                      | Italy                                  |
| Mentor  Medical Limited (U.K.)                                                                     | England                                |
| Mentor  Medical Systems (Canada), Inc.                                                             | Canada                                 |
| Mentor  Medical Systems B.V.                                                                       | Netherlands                            |
| Mentor  Medical Systems Ltd. (U.K.)                                                                | England                                |
| Mentor  Medical Systems Pty. Ltd.                                                                  | Australia                              |
| Mentor Medical Systems, C.V.                                                                       | Netherlands                            |
| Mentor  Medical Systems, France, S.A.                                                              | France                                 |
| Mentor  Medical Systems, Iberica, S.L.                                                             | Spain                                  |
| Mentor  Minnesota Inc. (Formerly Mentor Urology, Inc.)                                             | Delaware                               |
| Mentor  Ophthalmics, Inc. (Formerly Mentor O&O, Inc.)      (Dissolved 12/31/99) | Massachusetts                          |
| Mentor  ORC, Inc. (Dissolved 4/1/96)                                                               | Delaware                               |
| Mentor  Polymer Technologies Company                                                               | Texas                                  |
| Mentor Texas LP (Formerly Mentor H/S, Inc).                                                        | Delaware                               |
| Mills Biopharmaceuticals, Inc.                                                                     | Oklahoma                               |
| Porges (Belgium)                                                                                   | Belgium                                |
| Porges (Netherlands)                                                                               | Netherlands                            |
| Porges Co, Ltd.                                                                                    | Japan                                  |
| Porges GmbH                                                                                        | Germany                                |
| Porges S.A.                                                                                        | France                                 |
| Porges S.L.                                                                                        | Spain                                  |
| Porges S.R.L.                                                                                      | Italy                                  |
| Porges U.K. Ltd                                                                                    | England                                |
| Porges, Lda                                                                                        | Portugal                               |
| Sierra Laboratories,  Inc. (dissolved 3/20/02)                                                     | Arizona                                |
| Teknar  Corporation (dissolved 4/1/96)                                                             | Missouri                               |