<PAGE>
                                                                   Exhibit 10.46

                      AMENDMENT NO. 1 TO CREDIT AGREEMENT

THIS AMENDMENT NO. 1 TO CREDIT AGREEMENT (this "Amendment"), dated as of April
15, 2002, is entered into between Bank of America, N.A. ("Lender") and Meade
Instruments Corp., a Delaware corporation ("Borrower"), with reference to the
following facts:

                                    RECITALS

A.      Lender and Borrower are parties to that certain Credit Agreement, dated
        as of September 24, 2001 (the "Credit Agreement"), pursuant to which
        Lender provided Borrower with certain credit facilities.

B.      Borrower and Lender wish to amend the Credit Agreement as described
        below.

NOW, THEREFORE, the parties hereby agree as follows:

1.      Defined Terms. Any and all initially capitalized terms used in this
        Amendment (including, without limitation, in the recitals hereto)
        without definition shall have the respective meanings specified in the
        Credit Agreement.

2.      Amendment to Section 1.1. Section 1.1 of the Credit Agreement is amended
        to read in its entirety as follows:

               Subject to all of the terms and conditions of this Agreement, the
               Lender agrees to make available a total credit facility of up to
               $27,100,000 (the "Total Facility") to the Borrower from time to
               time during the term of this Agreement. The Total Facility shall
               be composed of a revolving line of credit consisting of Revolving
               Loans and Letters of Credit and the Term Loan described herein.
               Notwithstanding any term of this Agreement to the contrary,
               Borrower agrees that while Pricing Level V (as used in the
               definition of Applicable Margin) is in effect, Borrower may not
               request any new LIBOR Rate Loans. While Pricing Level V is in
               effect, any existing LIBOR Rate Loan will be converted into a
               Base Rate Loan upon conclusion of the Interest Period applicable
               to such LIBOR Rate Loan.

3.      Amendment to Section 7.22. Section 7.22 of the Credit Agreement is
        amended in its entirety to read as follows:

               7.22 Fixed Charge Coverage Ratio. The Borrower will maintain a
               Fixed Charge Coverage Ratio for each period of four consecutive
               fiscal quarters ending on the last day of each fiscal quarter set
               forth below of not less than the applicable ratio set forth
               below:

<TABLE>
<CAPTION>
                                                   Minimum Fixed
                      Fiscal Quarter Ending        Charge Coverage Ratio
                      ---------------------        ---------------------
                     <S>                          <C>
                      February 28, 2002            0.50 to 1.00

                      May 31, 2002                 0.50 to 1.00
</TABLE>


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<PAGE>

<TABLE>
                     <S>                          <C>
                      August 31, 2002              0.10 to 1.00

                      November 30, 2002 and
                      each Fiscal Quarter
                      ending thereafter            1.00 to 1.00

</TABLE>

4.      Amendment to Section 7.23. Section 7.23 of the Credit Agreement is
        amended in its entirety to read as follows:

               7.23 Adjusted Tangible Net Worth. Borrower will maintain Adjusted
               Tangible Net Worth of not less than the following amounts during
               the following periods:


<TABLE>
<CAPTION>
                                                   Minimum Adjusted
                      End of Month                 Tangible Net Worth
                      ---------------------        ---------------------
                     <S>                          <C>
                      Each month prior to
                      and including June 2002      $37,500,000

                      July 2002                    $38,000,000

                      August 2002                  $38,500,000

                      September 2002               $38,830,000

                      October 2002                 $39,383,000

                      November 2002 and each
                      month to and including
                      February 2003                $39,711,000

                      Each month after
                      February 2003                $39,711,000 plus 50% of positive
                                                   Net Income thereafter

</TABLE>

               "Net Income" means, with respect to any fiscal period of the
               Borrower, the Borrower's net income on a consolidated basis as
               determined in accordance with GAAP and reported on the Financial
               Statements for such period.

5.      Amendment to Section 7.25. Section 7.25 of the Credit Agreement is
        amended in its entirety to read as follows:

               7.25 US EBITDA. The Borrower will maintain US EBITDA for each
               period of four consecutive fiscal quarters ending on the last day
               of each fiscal quarter set forth below of not less than the
               applicable minimum US EBITDA set forth below:

<TABLE>
<CAPTION>
                     Fiscal Quarter Ending        Minimum US EBITDA
                     ---------------------        -------------------
                     <S>                          <C>
                      February 28, 2002            $2,000,000

</TABLE>


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<PAGE>

<TABLE>
                     <S>                          <C>
                      May 31, 2002                 $1,000,000

                      August 31, 2002               ($500,000)

                      November 30, 2002            $3,000,000

                      February 28, 2003            $3,075,000

                      May 31, 2003                 $3,250,000

                      August 31, 2003              $3,250,000

                      November 30, 2003            $3,500,000

                      February 29, 2004 and
                      each Fiscal Quarter
                      ending thereafter            $4,250,000
</TABLE>


6.      Amendments to Annex A. A definition for "Fixed Charge Coverage Ratio
        Shortfall Reserve" is added to Annex A of the Credit Agreement, and the
        definitions of "Applicable Margin", and "Maximum Revolver Amount" and
        "Reserves", as set forth in Annex A to the Credit Agreement are amended
        to read as follows:

               "Applicable Margin" means

               (i)    with respect to Base Rate Revolving Loans, Base Rate Term
                      Loans, and all other Obligations (other than LIBOR Loans),
                      1%;

               (ii)   with respect to LIBOR Revolving Loans, 3 1/4%; and

               (iii)  with respect to LIBOR Term Loans, 3 1/2%.

               The Applicable Margins shall be adjusted (up or down)
               prospectively on a quarterly basis as determined by the
               Borrower's consolidated financial performance, commencing with
               the first day of the first calendar month that occurs more than 5
               days after required delivery to Lender of the Borrower's draft
               audited Financial Statements to Lender for the Fiscal Year ending
               February 28, 2002. In the event the draft audited Financial
               Statements are subsequently determined to be in error, then any
               resulting change in the Applicable Margin shall be made
               retroactively to the date when the incorrect Applicable Margin
               was utilized. Adjustments in Applicable Margins shall be
               determined by reference to the following grids:


<TABLE>
<CAPTION>
                      IF FIXED CHARGE
                      COVERAGE RATIO               PRICING LEVEL
                      --------------               -------------
                     <S>                          <C>
                      Greater than 1.50 to 1.00    Level I

                      Greater than 1.25 to 1.00
                      but equal to or less than
                      1.50 to 1.00                 Level II
</TABLE>


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<PAGE>

<TABLE>
                     <S>                          <C>
                      Greater than 1.00 to 1.00
                      but equal to or less than
                      1.25 to 1.00                 Level III

                      Greater than 0.75 to 1.00
                      but equal to or less than
                      1.00 to 1.00                 Level IV

                      Equal to or less than
                      0.75 to 1.00                 Level V
</TABLE>


                               APPLICABLE MARGINS

<TABLE>
<CAPTION>
                                                   LEVEL I  LEVEL II   LEVEL III   LEVEL IV   LEVEL V
                                                   -------  --------   ---------   --------   -------
                      <S>                          <C>      <C>        <C>         <C>       <C>
                      Base Rate Loans               0.25%     0.50%      0.75%      1.25%      1.50%
                      LIBOR Revolving Loans         2.50%     2.75%      3.00%      3.50%      Not Avail.
                      LIBOR Term Loans              3.50%     3.50%      3.50%      3.50%      Not Avail.
</TABLE>


               All adjustments in the Applicable Margins after February 28,
               2002, shall be implemented quarterly on a prospective basis,
               commencing with the first day of the first calendar month that
               occurs more than 5 days after the required date of delivery to
               the Lender of quarterly unaudited or annual draft audited (as
               applicable) Financial Statements evidencing the need for an
               adjustment. In the event the draft audited Financial Statements
               are subsequently determined to be in error, then any resulting
               change in the Applicable Margin shall be made retroactively to
               the date when the incorrect Applicable Margin was utilized.
               Concurrently with the delivery of those Financial Statements, the
               Borrower shall deliver to the Lender a certificate, signed by its
               chief financial officer, setting forth in reasonable detail the
               basis for the continuance of, or any change in, the Applicable
               Margins. Failure to timely deliver such Financial Statements
               shall, in addition to any other remedy provided for in this
               Agreement, result in an increase in the Applicable Margins to the
               highest level set forth in the foregoing grid, until the first
               day of the first calendar month following the delivery of those
               Financial Statements demonstrating that such an increase is not
               required. If a Default or Event of Default has occurred and is
               continuing at the time any reduction in the Applicable Margins is
               to be implemented, no reduction may occur until the first day of
               the first calendar month following the date on which such Default
               or Event of Default is waived or cured.

               "Fixed Charge Coverage Ratio Shortfall Reserve" means $1,000,000
               at any time the Fixed Charge Coverage Ratio is less than 1.25 to
               1 for the period of four consecutive fiscal quarters ending on
               the last day of the fiscal quarter immediately prior to such
               time.

               "Maximum Revolver Amount" means $25,000,000.

               "Reserves" means reserves that limit the availability of credit
               hereunder, consisting of reserves against Availability, Eligible
               Accounts or Eligible Inventory, established by Lender from time
               to time in Lender's reasonable credit judgment. Without limiting
               the generality of the foregoing, the following


                                      -4-
<PAGE>

               reserves shall be deemed to be a reasonable exercise of Lender's
               credit judgment: (a) Bank Product Reserves; (b) a reserve for
               accrued, unpaid interest on the Obligations; (c) reserves for
               rent at leased locations subject to statutory or contractual
               landlord liens; (d) the Slow Moving Reserve; (e) the Dilution
               Adjustment Reserve; (f) warehousemen's or bailees' charges; and
               (g) the Fixed Charge Coverage Ratio Shortfall Reserve.

7.      Waiver of Default -- Section 7.23. Compliance with Section 7.23 of the
        Credit Agreement (as in effect prior to this Amendment) is hereby waived
        in respect of Borrower complying with the Adjusted Tangible Net Worth
        requirement for the period from November 30, 2001 through January 31,
        2002.

8.      Waiver of Default -- Section 7.25. Compliance with Section 7.25 of the
        Credit Agreement (as in effect prior to this Amendment) is hereby waived
        in respect of Borrower complying with the US EBITDA requirement for the
        period from November 30, 2001 through January 31, 2002.

9.      No Other Waivers. The waivers contained in Section 7 and Section 8 of
        this Amendment are expressly limited to the facts and circumstances
        referred to therein and shall not operate as a waiver of or a consent to
        non-compliance with any other section of the Credit Agreement or any of
        the other Loan Documents. The waivers contained in Section 7 and Section
        8 are only effective for the specific instances, for the specific
        purposes and for the specific periods for which given.

10.     Representations and Warranties of Borrower. Borrower represents and
        warrants that: (a) after giving effect to the Amendment no Default or
        Event of Default exists as of the date of this Amendment; and (b) no
        Default or Event of Default will result as a consequence of the
        transactions contemplated by this Amendment.

11.     Conditions Precedent. The effectiveness of this Amendment shall be
        subject to the prior satisfaction of all of the following conditions:

        (a)    Execution and Delivery of this Amendment. Lender shall have
               received an original of this Amendment, duly executed by
               Borrower.

        (b)    Consent and Reaffirmation of Guarantors. Each Guarantor shall
               have confirmed the continuing validity and effectiveness of the
               Continuing Guaranty dated as of September 24, 2001, by executing
               and delivering to Lender its Consent and Reaffirmation of
               Continuing Guaranty in the form of Exhibit "A" attached to this
               Amendment.

        (c)    Execution and Delivery of Certificate of Resolution. The Agent
               shall have received an original Certificate of Resolution, in the
               form of Exhibit "B", duly executed by the Secretary of Borrower.

        (d)    Amendment Fee. Lender shall have received an amendment fee of
               $50,000 in immediately available funds. Borrower acknowledges and
               agrees that this amendment fee is fully earned and nonrefundable
               upon receipt by Lender. Borrower acknowledges and agrees that
               Lender may effect payment of this amendment fee by charging the
               full amount thereof to Borrower's revolving loan account as a
               $50,000 Revolving Loan under the Agreement.

        (e)    Execution and Delivery of Other Documents. Borrower shall have
               executed and delivered to the Agent such other documents and
               instruments as the Agent may require.


                                      -5-
<PAGE>

12.     Miscellaneous.

        (a)    Survival of Representations and Warranties. All representations
               and warranties made in the Credit Agreement or in any other
               document or documents relating thereto, including without
               limitation, any Loan Document furnished in connection with this
               Amendment, shall survive the execution and delivery of this
               Amendment and the other Loan Documents, and no investigation by
               Lender or any closing shall affect the representations and
               warranties or the right of Lender to rely thereon.

        (b)    Reference to Credit Agreement. The Credit Agreement, each of the
               other Loan Documents, and any and all other agreements, documents
               or instruments now or hereafter executed and delivered pursuant
               to the terms hereof, or pursuant to the terms of the Credit
               Agreement as amended hereby, are hereby amended so that any
               reference therein to the Credit Agreement shall mean a reference
               to the Credit Agreement as amended hereby.

        (c)    Credit Agreement Remains in Effect. The Credit Agreement and the
               other Loan Documents remain in full force and effect and Borrower
               ratifies and confirms its agreements and covenants contained
               therein. Borrower hereby confirms that, after giving effect to
               this Amendment, no Event of Default or Default exists as of such
               date.

        (d)    Severability. Any provision of this Amendment held by a court of
               competent jurisdiction to be invalid or unenforceable shall not
               impair or invalidate the remainder of this Amendment and the
               effect thereof shall be confined to the provision so held to be
               invalid or unenforceable.

        (e)    Applicable Law. This Amendment and all other Loan Documents
               executed pursuant hereto shall be deemed to have been made and to
               be performable in the State of California and shall be governed
               by and construed in accordance with the internal laws (as opposed
               to the conflict of law provisions) of the State of California.

        (f)    Successors and Assigns. This Amendment is binding upon and shall
               inure to the benefit of Lender and Borrower and their respective
               successors and assigns; provided, however, that Borrower may not
               assign or transfer any of its rights or obligations hereunder
               without the prior written consent of Lender.

        (g)    Counterparts. This Amendment may be executed in one or more
               counterparts, each of which when so executed shall be deemed to
               be an original, but all of which when taken together shall
               constitute one and the same instrument.

        (h)    Execution by Facsimile. Facsimile transmission of a signed
               original of this Amendment or retransmission of any signed
               facsimile transmission or of any Loan Document will be deemed the
               same as delivery of an original. At the request of any other
               party, each of the undersigned will confirm facsimile
               transmission by signing a duplicate original document.

        (i)    Headings. The headings, captions and arrangements used in this
               Amendment are for convenience only and shall not affect the
               interpretation of this Amendment.

        (j)    Expenses of Lender. Borrower agrees to pay on demand (i) all
               costs and expenses reasonably incurred by Lender in connection
               with the preparation, negotiation and execution of this Amendment
               and the other Loan Documents executed pursuant hereto and any and
               all subsequent amendments, modifications, and supplements hereto
               or thereto, including, without limitation, the costs and fees of
               Lender's legal counsel and the


                                      -6-
<PAGE>

               allocated cost of Lender's in-house counsel and (ii) all costs
               and expenses reasonably incurred by Lender in connection with the
               enforcement or preservation of any rights under the Credit
               Agreement, this Agreement or any other Loan Documents, including,
               without limitation, the costs and fees of Lender's legal counsel
               and the allocated cost of Lender's in-house counsel.

        (k)    Miscellaneous Terms. The term "or" is disjunctive; the term "and"
               is conjunctive. The term "shall" is mandatory; the term "may" is
               permissive. Masculine terms also apply to females; feminine terms
               also apply to males. The term "including" is by way of example
               and not limitation.

        (l)    NO ORAL AGREEMENTS. THIS AMENDMENT, TOGETHER WITH THE OTHER LOAN
               DOCUMENTS AS WRITTEN, REPRESENTS THE FINAL AGREEMENT BETWEEN
               LENDERS AND BORROWER AND MAY NOT BE CONTRADICTED BY EVIDENCE OF
               PRIOR, CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE
               PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN LENDERS
               AND BORROWER.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]


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<PAGE>

IN WITNESS WHEREOF, the parties have entered into this Amendment by their
respective duly authorized officers as of the date first above written.

                                        LENDER:

                                        BANK OF AMERICA, N.A.



                                        By:        /s/ Todd Eggertsen
                                               -------------------------------

                                        Name:      Todd Eggertsen
                                               -------------------------------

                                        Title:     Assistant Vice President
                                               -------------------------------

                                        BORROWER:

                                        MEADE INSTRUMENTS CORP.,
                                        a Delaware corporation

                                        By:        /s/ Brent W. Christensen
                                               -------------------------------

                                        Name:      Brent W. Christensen
                                               -------------------------------

                                        Title:     Chief Financial Officer
                                               -------------------------------


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