**EXHIBIT31.1**

**§302CERTIFICATION**

I, Joshua H. Levine, certify that:

1.    I have reviewed thisquarterly report on Form 10-Q of Mentor Corporation;

2.    Based on my knowledge, thisquarterly report does not contain any untrue statement of a material fact or omit to statea material fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading with respectto the period covered by this report;

3.    Based on my knowledge, thefinancial statements, and other financial information included in this quarterly report,fairly present in all material respects the financial condition, results ofoperations and cash flows of the registrant as of, and for, the periodspresented in this report;

4.    The registrant's othercertifying officer(s) and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e)and 15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant andhave:

(a)   Designed such disclosure controls and procedures, orcaused such disclosure controls and procedures to be designed under oursupervision, to ensure that material information relating to the registrant,including its consolidated subsidiaries, is made known to us by others withinthose entities, particularly during the period in which this quarterly report is beingprepared;

(b)   Designed such internal control over financialreporting, or caused such internal control over financial reporting to bedesigned under our supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financial statementsfor external purposes in accordance with generally accepted accountingprinciples;

(c)   Evaluated the effectiveness of the registrant'sdisclosure controls and procedures and presented in this report our conclusionsabout the effectiveness of the disclosure controls and procedures, as of the endof the period covered by this quarterly report based on such evaluation; and

(d)   Disclosed in this quarterly report any change in theregistrant's internal control over financial reporting that occurred during theregistrant's most recent fiscal quarter (the registrant's fourth fiscal quarterin the case of an annual report) that has materially affected, or is reasonablylikely to materially affect, the registrant's internal control over financialreporting; and

5.    The registrant's othercertifying officer(s) and I have disclosed, based on our most recent evaluationof internal control over financial reporting, to the registrant's auditors andthe audit committee of the registrant's board of directors (or personsperforming the equivalent function):

(a)   Allsignificant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely toadversely affect the registrant's ability to record, process, summarize andreport financial information; and

(b)   Any fraud,whether or not material, that involves management or other employees who have asignificant role in the registrant's internal control over financialreporting.

| Date:  August 8, 2005 | /s/JOSHUA H. LEVINE                                                                    |
|----------------------------|----------------------------------------------------------------------------------------|
|                       | Joshua H. Levine		President and Chief Executive Officer		(Principal Executive Officer) |