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                                  EXHIBIT 99.1

                               CYRAS SYSTEMS, INC.
                 _________, 2001 SPECIAL MEETING OF STOCKHOLDERS
                        PROXY FOR HOLDERS OF COMMON STOCK
               PROXY SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS


The undersigned hereby appoints ______________, ________________ and
____________ and each of them, with full power of substitution, to represent the
undersigned and to vote all the shares of stock in Cyras Systems, Inc., a
Delaware corporation (the "Company" or "Cyras"), which the undersigned is
entitled to vote at the Special Meeting of Stockholders of said Company to be
held on __________, 2001 at the Fremont Marriott, 46100 Landing Parkway,
Fremont, California at _____ a.m. local time, and any adjournment or
postponement thereof, (1) as hereinafter specified upon Proposal 1 listed below
and as more particularly described in the Prospectus and Proxy Statement dated
__________, 2001, receipt of which is hereby acknowledged, and (2) in their
discretion upon such other matters as may properly come before the meeting,
including any motion to adjourn to permit further solicitation of proxies if
necessary, or any postponements or adjournments thereof.

THE SHARES REPRESENTED HEREBY SHALL BE VOTED UPON PROPOSAL 1 AS SPECIFIED. IF NO
SPECIFICATION IS MADE, SUCH SHARES SHALL BE VOTED FOR PROPOSAL 1 AND AS SAID
PROXIES DEEM ADVISABLE ON SUCH OTHER MATTERS AS MAY PROPERLY COME BEFORE THE
MEETING, INCLUDING ANY MOTION TO ADJOURN TO PERMIT FURTHER SOLICITATION OF
PROXIES, IF NECESSARY, TO ESTABLISH A QUORUM OR TO OBTAIN ADDITIONAL VOTES IN
FAVOR OF THE ISSUANCE OF SHARES OF CYRAS COMMON STOCK, OR ANY POSTPONEMENTS OR
ADJOURNMENTS THEREOF.

/X/  PLEASE MARK VOTES AS IN THIS EXAMPLE

The Board of Directors of Cyras Systems, Inc. recommends a vote FOR the
following proposals:

1.      To approve and adopt the Agreement and Plan of Merger dated as of
        December 18, 2000 by and among Cyras, CIENA Corporation and CO
        Acquisition Corp., a wholly owned subsidiary of CIENA, and to
        approve the merger of Cyras with CO Acquisition Corp.; whereby holders
        of Cyras stock will receive for each share of Cyras stock held a
        fraction of a share of CIENA Corporation common stock based on a formula
        described in the Prospectus and Proxy Statement and in the Agreement and
        Plan of Merger referred to above.

           /  /  FOR            /  /  AGAINST                /  /  ABSTAIN
        CONTINUED AND TO BE SIGNED ON REVERSE SIDE SEE REVERSE SIDE



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2.      To grant Cyras's board of directors discretionary authority to adjourn
        the special meeting to solicit additional votes for approval of the
        merger.

           /  /  FOR            /  /  AGAINST                /  /  ABSTAIN

3.      To transact any other business that may properly come before the special
        meeting or any adjournments or postponements of the special meeting.

           /  /  FOR            /  /  AGAINST                /  /  ABSTAIN

        MARK HERE FOR ADDRESS CHANGE AND NOTE AT LEFT.  /  /
        MARK HERE IF YOU PLAN TO ATTEND THE MEETING.  /  /

WHETHER OR NOT YOU PLAN TO ATTEND THE MEETING IN PERSON, YOU ARE URGED TO SIGN
AND PROMPTLY MAIL THIS PROXY IN THE RETURN ENVELOPE SO THAT YOUR STOCK MAY BE
REPRESENTED.

Please sign below. If shares of stock are held jointly, both or all of such
persons should sign. Corporate or partnership proxies should be signed in full
corporate or partnership name by an authorized person. Persons signing in a
fiduciary capacity should indicate their full title in such capacities.

                             Signature:
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                             Date:
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                             Signature:
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                             Date:
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