**EXHIBIT 31.1**
**§302 CERTIFICATION**
I, Joshua H. Levine, certify that:
1. I have reviewed this Annual Report on Form 10-K of Mentor Corporation;
2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state amaterial fact necessary to make the statements made, in light of the circumstances under which such statements weremade, not misleading with respect to the period covered by this report;
3. Based on my knowledge, the financial statements, and other financial information included in this report, fairlypresent in all material respects the financial condition, results of operations and cash flows of the registrant as of,and for, the periods presented in this report;
4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosurecontrols and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financialreporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:
(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures tobe designed under our supervision, to ensure that material information relating to the registrant, includingits consolidated subsidiaries, is made known to us by others within those entities, particularly during theperiod in which this report is being prepared;
(b) Designed such internal control over financial reporting, or caused such internal control over financialreporting to be designed under our supervision, to provide reasonable assurance regarding the reliability offinancial reporting and the preparation of financial statements for external purposes in accordance withgenerally accepted accounting principles;
(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented inthis report our conclusions about the effectiveness of the disclosure controls and procedures, as of the endof the period covered by this report based on such evaluation; and
(d) Disclosed in this report any change in the registrant’s internal control over financial reporting thatoccurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in thecase of an annual report) that has materially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and
5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internalcontrol over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board ofdirectors (or persons performing the equivalent function):
(a) All significant deficiencies and material weaknesses in the design or operation of internal controlover financial reporting which are reasonably likely to adversely affect the registrant’s ability to record,process, summarize and report financial information; and
(b) Any fraud, whether or not material, that involves management or other employees who have a significantrole in the registrant’s internal control over financial reporting.   Date: May 30, 2008 /s/ JOSHUA H. LEVINE  Joshua H. Levine  President and Chief Executive Officer  (Principal Executive Officer)