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                                                                   EXHIBIT 10.13

                         REGISTRATION RIGHTS AGREEMENT

     THIS REGISTRATION RIGHTS AGREEMENT ("Agreement") between ION LASER
TECHNOLOGY, INC., a Utah corporation (the "Company"), and LCO INVESTMENTS
LIMITED, a company organized under the laws of Guernsey, Channel Islands
("LCO"), is made and entered into as of May 4, 1998.  LCO is referred to herein
as "Holder".

                                    RECITALS

     A.   The Company and Holder have entered into that certain Stock Purchase
Agreement (the "Purchase Agreement") of even date with this Agreement, pursuant
to which Holder has agreed to purchase and the Company has agreed to sell shares
of its Common Stock, par value $.001 per share (the "Shares"), which Shares
(the "Registrable Securities") are now  restricted and not registered under the
Securities Act of 1933, as amended, (the "Act") or under the provisions of any
state securities law.

     B.   Holder would not have agreed to execute the Purchase Agreement or to
consummate the transactions contemplated by the Purchase Agreement unless the
Company had agreed to enter into this Agreement.

                                   AGREEMENT

     In consideration of the promises contained in this Agreement and in the
Purchase Agreement, and for other good and valuable consideration, the receipt
and sufficiency of which the parties acknowledge by their signatures below, the
Company and Holder agree as follows:


     1.   Piggyback Registrations.  If at any time after 180 days from the date
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of this Agreement the Company proposes to file a registration statement covering
proposed sales by it or any of its shareholders of shares of its capital stock
in a manner which would permit registration of shares of common stock for sale
to the public (other than a registration statement (i) covering only shares
issuable upon (a) the exercise of employee stock options or pursuant to an
employee stock purchase, dividend reinvestment or similar plan, or (b) the
exercise of a convertible security, or (ii) under a Registration Statement filed
on Form S-4 or S-8 or any similar form under the Act or (iii) pursuant to
Section 2, below), the Company will give prompt notice to Holder of such
proposed registration (which notice shall describe the proposed filing date and
the date by which the registration rights granted pursuant to this Section 1
must be exercised, the nature and method of any such sale or disposition of
securities and shall include a listing of the jurisdictions, if any, in which
the Company proposes to register or qualify the securities under the applicable
state securities or "Blue Sky" laws of such jurisdictions).  At the request of
Holder given within thirty (30) calendar days after the receipt of such notice
by Holder (which request shall specify the number of shares Holder requests to
be included in such registration), the
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Company will use its best efforts to cause all shares as to which registration
has been requested by Holder to be included in such registration statement for
sale or disposition in accordance with the method described in the initial
notice given to Holder and subject to the same terms and conditions as the other
shares of capital stock being sold, and thereafter shall cause such registration
statement to be filed and become effective; provided, however, that the Company
shall be permitted to (A) withdraw the registration statement for any reason in
its sole and exclusive discretion and upon the written notice of such decision
to Holder shall be relieved of all of its obligations under this Section 1 with
respect to that particular registration; or (B) exclude all or any portion of
the shares sought to be registered by Holder from such registration statement if
the offering of the shares is an underwritten offering and to the extent that,
in the judgment of the managing underwriter of the offering, the inclusion of
such shares would be materially detrimental to the offering of the remaining
shares of capital stock, or such delay is necessary in light of market
conditions. Any shares sought to be registered by Holder so excluded from a
registration statement shall be excluded pro rata based on the total number of
shares of capital stock being sold by all selling security holders (other than
the Company).

     2.   Demand Registration.  If at any time after 180 days from the date of
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this Agreement the Company shall be requested in writing by LCO (and LCO then
holds any issued and outstanding Registrable Securities at such time) to effect
the registration under the Act of shares of the Company's Common Stock then
owned by Holder (which request shall specify the aggregate number of shares
intended to be offered and sold by Holder, shall describe the nature or method
of the proposed offer and sale thereof and shall contain an undertaking by
Holder to cooperate fully with the Company in order to permit the Company to
comply with all applicable requirements of the Act and the rules and regulations
thereunder and to obtain acceleration of the effective date of the registration
statement contemplated thereby), the Company shall effect the registration of
such securities on an appropriate form under the Act, provided that:

          2.1  LCO's rights under this Section 2 shall be exercisable only if
the shares as to which LCO requests registration have an aggregate value of at
least $500,000 based on the average of the closing sale price for the Company's
common stock as listed on the American Stock Exchange or any other exchange on
which the Company's common stock then may be traded for the thirty (30) trading-
day period immediately preceding the date of such request for registration;

          2.2  The independent members of the Company's Board of Directors, with
the advice of such investment bankers or securities professionals as the Board
shall deem necessary, shall have determined in good faith that the cost of
complying with the request for registration under this Section 2 would not have
a materially adverse effect upon the Company, its operations or the market for
the Company's common stock, provided, however, that if the independent members
of the Company's Board of Directors determine in good faith that the cost of
complying with the request for registration would have a material adverse effect
upon the Company, its operations or the market for the Company's common stock,
the Company may decline Holder's request to register Holder's Registrable
Securities under the Act, provided further, however, that in such event the
Company may not thereafter again decline LCO's request for registration based

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upon this Section so long as such subsequent request is received by the Company
more than 120 days after LCO's request for registration which was declined based
upon this Section;

          2.3  LCO shall be entitled to three demand registrations, provided
that registrations two and three may be effected on Form S-3 or its then
equivalent form promulgated by the SEC and, provided further, that any request
for registration pursuant to this Section 2 which does not result in the
declaration of effectiveness of a registration statement (which effectiveness is
maintained continuously for at least 120 days or such shorter period ending when
all shares to which LCO has requested registration in accordance herewith have
been sold in accordance with such registration) covering the offer and sale of
shares owned by Holder and requested to be included in such registration
statement, whether as a result of the withdrawal of the registration statement
by the Company or through other action or inaction of the Company or for any
other reason except for the voluntary decision of Holder to terminate the
registration after the request for such registration has been delivered to the
Company, shall not be counted in determining the number of times registration
rights have been exercised pursuant to this Section 2;

          2.4  The Company shall be entitled to postpone the filing of any
registration statement otherwise required to be prepared and filed by it
pursuant to this Section 2, if at the time it receives a request for such
registration, the independent members of the Company's Board of Directors
determine that such registration and offering would materially interfere with
any existing or then presently contemplated financing, acquisition, corporate
reorganization or other material transaction involving the Company, and the
Company promptly gives LCO written notice of such determination, provided,
however, that such postponement shall not extend beyond the time that such
material interference continues to exist; and

          2.5  LCO shall have no right to demand registration with respect to
any shares within ninety (90) calendar days after the effective date of any
registration statement previously filed by the Company, other than a
registration statement on Form S-8 or similar form.

     3.   Registration Procedures.  If and whenever this Agreement contemplates
          -----------------------                                              
that the Company will effect the registration under the Act of any shares held
by Holder, the Company shall:

          3.1  prepare and file with the Securities and Exchange Commission (the
"SEC") a registration statement on the appropriate form with respect to such
shares and use its best efforts to cause such registration statement to become
and remain effective as provided herein, provided that before filing any
amendments or supplements to a registration statement or prospectus, including
documents incorporated by reference after the initial filing of the registration
statement, the Company will furnish to Holder and the underwriters, if any,
copies of all such documents proposed to be filed at least five business days
prior thereto, which documents will be subject to the reasonable review of
Holder and underwriters, and the Company will not file an amendment to a
registration statement or prospectus or any supplement

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thereto (including such documents incorporated by reference) to which Holder or
the underwriters, if any, shall reasonably object;

          3.2  prepare and file with the SEC such amendments and supplements to
such registration statement and the prospectus used in connection therewith and
to take such other action as may be necessary to keep such registration
statement effective until the earlier of (i) the completion of the distribution
of shares so registered, or (ii) expiration of the 120 day period following
immediately the effective date of such registration statement (at which time
unsold shares may be deregistered), and otherwise comply with applicable
provisions of the Act and the rules and regulations promulgated under the Act;

          3.3  furnish to Holder and its counsel, and to each underwriter of the
shares to be sold by Holder, without charge, such number of copies of one or
more preliminary prospectuses, any supplements thereto and a final prospectus
and any supplements thereto in conformity with the requirements of the Act, and
such other documents as Holder or such underwriter may reasonably request, in
order to facilitate the public sale or other disposition of such shares;

          3.4  if, during any period in which, in the opinion of the Company's
counsel, a prospectus relating to the shares is required to be delivered under
the Act in connection with any offer or sale contemplated by any registration
statement, any event known to the Company occurs as a result of which the
prospectus would include an untrue statement of material fact or omit to state
any material fact necessary to make the statements made therein, in light of the
circumstances under which they were made, not misleading, or if it is necessary
at any time to amend or supplement the related prospectus to comply with the
Act, the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or
the respective rules and regulations thereunder, to notify Holder promptly and
to prepare and file with the SEC an amendment or supplement, whether by filing
such documents pursuant to the Act or the Exchange Act as may be necessary to
correct such untrue statement or omission or to make any registration statement
or the related prospectus comply with such requirements and to furnish to Holder
and its counsel such amendment or supplement to such registration statement or
prospectus;

          3.5  timely to file with the SEC (i) any amendment or supplement to
any registration statement or to any related prospectus that is required by the
Act or the Exchange Act or requested by the SEC, and (ii) all documents (and any
amendments to previously filed documents) required to be filed by the Company
pursuant to Section 13(a), 13(c), 14 and 15(d) of the Exchange Act;

          3.6  within five days of filing with the SEC of (i) any amendment or
supplement to any registration statement, (ii) any amendment or supplement to
the related prospectus, or (iii) any document incorporated by reference in any
of the foregoing or any amendment of or supplement to any such incorporated
document, to furnish a copy thereof to Holder;

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          3.7  to advise Holder and its counsel promptly (i) when any post-
effective amendment to any registration statement becomes effective and when any
further amendment of or supplement to the prospectus shall be filed with the
SEC, (ii) of any request or proposed request by the SEC for an amendment or
supplement to any registration statement, to the related prospectus, to any
document incorporated by reference in any of the foregoing or for any additional
information, (iii) of the issuance by the SEC of any stop order suspending the
effectiveness of any registration statement or any order directed to the related
prospectus or any document incorporated therein by reference or the initiation
or threat of any stop order proceeding or of any challenge to the accuracy or
adequacy of any document incorporated by reference in such prospectus, (iv) of
receipt by the Company of any notification with respect to the suspension of the
qualification of the shares for sale in any jurisdiction or the initiation or
threat of any proceeding for such purpose, and (v) of the happening of any event
which makes untrue any statement of a material fact made in any registration
statement or the related prospectus as amended or supplemented or which requires
the making of a change in such registration statement or such prospectus as
amended or supplemented in order to make any material statement therein not
misleading;

          3.8  on or before the date a registration statement is declared
effective, use its best efforts to register or qualify the shares covered by
such registration statement under the securities or blue sky laws of such
jurisdictions as Holder shall reasonably request, considering the nature and
size of the offering, and do such other acts and things as may be reasonably
necessary to enable Holder to consummate the public sale or other disposition in
each such jurisdiction of such shares; provided, however, that the Company shall
not be obligated to qualify as a foreign corporation to do business under the
laws of any jurisdiction in which it has not been qualified, or to file any
general consent to service of process;

          3.9  use its best efforts to cause all shares sold pursuant to any
registration statement to be listed on each national securities exchange, if
any, on which such shares are then listed;

          3.10 enter into customary agreements (including, if applicable, an
underwriting agreement in customary form) and take such other actions as are
reasonably required in order to expedite or facilitate the disposition of such
Registrable Securities;

          3.11 make reasonably available for inspection by Holder, any
underwriter participating in any disposition pursuant to the registration
statement, and any attorney, accountant or other agent retained by Holder or
underwriter (collectively, the "Inspectors"), all pertinent financial and other
records, pertinent corporate documents and properties of the Company
(collectively, the "Records") as shall be reasonably necessary to enable them to
exercise their due diligence responsibility, and cause the Company's officers,
directors and employees to supply all information reasonably requested by any
such Inspector in connection with such registration statement.  Records and
other information which the Company determines, in good faith, to be
confidential and which it notifies the Inspectors are confidential shall not be
disclosed by the Inspectors unless (i) the disclosure of such Records, in the
opinion of counsel 

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reasonably acceptable to the Company, is necessary to avoid or correct a
misstatement or omission in the registration statement, or (ii) the release of
such records is ordered pursuant to a subpoena or other order from a court of
competent jurisdiction. Holder agrees that it will, upon learning that
disclosure of such Records is sought in a court of competent jurisdiction, give
notice to the Company and allow the Company, at the Company's expense, to
undertake appropriate action to prevent disclosure of the Records deemed
confidential;

          3.12 use its best efforts to obtain a "cold comfort" letter from the
Company's independent public accountants in customary form and covering such
matters of the type customarily covered by "cold comfort" letters as Holder, or
the managing underwriter, reasonably requests;

          3.13 use its best efforts to obtain an opinion or opinions from
counsel for the Company in customary form;

          3.14 make every reasonable effort to obtain the withdrawal of any
order suspending the effectiveness of the registration statement at the earliest
possible moment; and

          3.15 cooperate with Holder and the managing underwriter or
underwriters, if any, to facilitate the timely preparation and delivery of
certificates (not bearing any restrictive legends) representing securities to be
sold under the registration statement, and enable such securities to be in such
denominations and registered in such names as the managing underwriter or
underwriters, if any, or Holder may request.

     4.   Agreements of Holder.  Holder (i) upon receipt of a notice from the
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Company of the occurrence of any event of the kind described in Subsection 3.4
shall forthwith discontinue Holder's disposition of securities included in the
registration statement until Holder receives copies of the supplemented or
amended prospectus, and (ii) if so directed by the Company, shall deliver to the
Company, at the Company's expense, all copies (other than permanent file copies)
then in Holder's possession of the prospectus covering such securities that was
in effect at the time of receipt of such notice.

     5.   Withdrawal.  If Holder disapproves of the terms of any offering, the
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sole remedy of Holder shall be to withdraw Holder's securities therefrom by
giving written notice to the Company and any managing underwriter (if any).
Holder's securities of the Company so withdrawn from the offering also shall be
withdrawn from registration.

     6.   Participation in Underwritten Registrations.  In the case of any
          -------------------------------------------                     
registration under Section 2, if Holder or the Company determines to enter into
an underwriting agreement in connection therewith, or in the case of a
registration under Section 1, if the Company determines to enter into an
underwriting agreement in connection therewith, (i) all shares of Holder's
securities to be included in such registration shall be subject to an
underwriting agreement, which shall be in customary form and contain such terms
as are customarily contained in such agreements, and (ii) no person may
participate in any such registration unless such person (A)

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agrees to sell such person's securities on the basis provided in such
underwriting arrangement, and (B) completes and executes all questionnaires,
powers-of-attorney, indemnities, underwriting agreements and other documents
reasonably required under the terms of such underwriting arrangements.

     7.   Registration Expenses.  With respect to each registration effected
          ---------------------                                             
pursuant to Section 1 and to each registration under Section 2 of this
Agreement, the Company shall pay the following fees, disbursements and expenses:
all registration and filing fees, printing expenses, auditors' fees, listing
fees, registrar and transfer agent's fees, fees and disbursements of counsel to
the Company, reasonable fees and disbursements of not more than one counsel to
Holder in the case of each registration under Section 2 of this Agreement,
expenses (including reasonable fees and disbursements of counsel) of complying
with applicable securities or "Blue Sky" laws, and the fees of any securities
exchange in connection with the review of such offering.  The underwriting
discounts and commissions allocable to the shares included in any offering shall
be borne by Holder.

     8.   Indemnification.
          --------------- 

          8.1  In each case of a registration of shares under the Securities Act
pursuant to this Agreement, the Company will indemnify and hold harmless Holder,
its officers and directors, each underwriter (as defined in the Act), and each
other person, if any, who controls Holder or any such underwriter within the
meaning of the Act or the Exchange Act, from and against any and all losses,
claims, damages and liabilities (including the fees and expenses of counsel in
connection therewith), arising out of any untrue statement or alleged untrue
statement of a material fact contained in any registration statement under which
such shares were registered under the Act, any prospectus or preliminary
prospectus contained therein, or any amendment or supplement thereto (including,
in each case, documents incorporated by reference therein), or arising out of
any omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements made therein not misleading,
except insofar as such losses, claims, damages or liabilities arise out of any
such untrue statement or omission or alleged untrue statement or omission based
upon information relating to Holder, Holder's counsel, or any underwriter, and
furnished to the Company in writing by Holder or such counsel or underwriter;
provided that the foregoing indemnification with respect to a preliminary
prospectus shall not inure to the benefit of any underwriter (or the benefit of
any person controlling such underwriter) from whom the person asserting any such
losses, claims, damages or liabilities purchased shares to the extent such
losses, claims, damages or liabilities result from the fact that a copy of the
final prospectus had not been sent or given to such person at or prior to
written confirmation of the sale of such shares to such person.

          8.2  In each case of a registration of shares under the Act pursuant
to this Agreement, Holder will indemnify and hold harmless the Company, its
directors, its officers who sign the registration statement, its attorneys, each
underwriter and each person, if any, who controls the Company or such
underwriter within the meaning of the Act or the Exchange Act, to the same
extent as the foregoing indemnity from the Company to Holder, but only with
reference

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to information provided to the Company in writing by Holder and furnished to the
Company by Holder expressly for use in the registration statement, any publicly
available report of Holder published within the time frame of the registration
statement, any prospectus or preliminary prospectus contained therein, or any
amendment or supplement thereto.

          8.3  In case any proceeding (including any governmental investigation)
shall be instituted involving any person in respect of which indemnity may be
sought pursuant to this Section 8, such person (the "Indemnified Party") shall
promptly notify the person against whom such indemnity may be sought (the
"Indemnifying Party") in writing and the Indemnifying Party, upon request of the
Indemnified Party, shall retain counsel reasonably satisfactory to the
Indemnified Party to represent the Indemnified Party and any others the
Indemnifying Party may designate in such proceeding and shall pay the fees and
disbursements of such counsel related to such proceeding.  In any such
proceeding, any Indemnified Party shall have the right to retain its own
counsel, but the fees and expenses of such counsel shall be at the expense of
such Indemnified Party unless (i) the Indemnifying Party has agreed to the
retention of such counsel at its expense, or (ii) the named parties to any such
proceeding (including any impleaded parties) include both the Indemnifying Party
and the Indemnified Party, the Indemnifying Party proposes that the same counsel
represent both the Indemnified Party and the Indemnifying Party and
representation of both parties by the counsel would be inappropriate due to
actual or potential differing interests between them.  It is understood, where
the expense of separate counsel shall be borne by the Indemnifying Party
pursuant to the foregoing sentence, that the Indemnifying Party shall not, in
connection with any proceeding or related proceedings in the same jurisdiction,
be liable for the fees and expenses of more than one separate firm qualified in
such jurisdiction to act as counsel for such Indemnified Party.  The
Indemnifying Party shall not be liable for any settlement of any proceeding
effected without its written consent, but if settled with such consent or if
there be a final judgment for the plaintiff, the Indemnifying Party agrees to
indemnify the Indemnified Party from and against any loss or liability by reason
of such settlement or judgment.

          8.4  The indemnification pursuant to this Section 8 shall be on such
other terms and conditions as are at the time customary and reasonably required
by underwriters in public offerings, including providing for contribution in the
event indemnification provided in this Section 8 is unavailable or insufficient.

     9.   Holdback Agreement.  Holder agrees not to effect any public sale or
          ------------------                                                 
distribution of the Company's shares of capital stock during the seven (7)
calendar days prior to and the ninety (90) calendar day period beginning on the
effective date of any underwritten registration statement effected pursuant to
this Agreement (except as part of such underwritten registration) unless the
managing underwriter or underwriters with respect to such offering otherwise
agree.

     10.  Selection of Underwriters.  The Company will have the right to select
          -------------------------                                            
the investment banking firm(s) acting as managing underwriter in connection with
any underwritten public offering; provided, that in the event the offering is
                                  --------                                   
pursuant to a demand registration hereunder, Holder shall have the sole right to
select such managing underwriter.

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     11.  Survival.  The indemnification provisions of Section 8 shall not
          --------                                                        
terminate and shall survive forever.

     12.  Rule 144.  The Company agrees that it will use its best efforts to
          --------                                                          
file in a timely manner all reports required to be filed by it pursuant to the
Exchange Act and, at any time and upon request of Holder, will furnish Holder
and others with such information as may be necessary to enable Holder to effect
sales of Registrable Securities without registration pursuant to Rule 144 under
the Act.

     13.  General.
          ------- 

          13.1 Assignment.  Except in connection with the transfer by Holder of
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not less than 100,000 shares of Common Stock, Holder's rights under this
Agreement shall not be transferable without the written consent of the Company;
provided that LCO may assign its rights under this Agreement to one or more
affiliates or to one or more charitable foundations who agree to be bound by
this Agreement as if they were LCO.  Any attempted assignment or other transfer
of this Agreement in contravention of this Section 13.1 shall be null and void.

          13.2 Counterparts.  This Agreement may be executed in one or more
               ------------                                                
counterparts, each of which when so signed shall be deemed to be an original,
and such counterparts together shall constitute one and the same instrument.

          13.3 Entire Agreement.  This Agreement sets forth the entire agreement
               ----------------                                                 
between the parties as to the subject matter hereof, supersedes any and all
prior or contemporaneous agreements or understandings of the parties relating to
the subject matter of this Agreement, and may not be amended except by an
instrument in writing signed by all of the parties to this Agreement.

          13.4 Governing Law.  The laws of the State of Utah (without giving
               -------------                                                
effect to the choice of law provisions thereof) shall govern the interpretation
and enforcement of this Agreement.

          13.5 Headings.  The headings of the sections and paragraphs of this
               --------                                                      
Agreement have been inserted for convenience of reference only and do not
constitute a part of this Agreement.

          13.6 Notices.  All notices or other communications provided for under
               -------                                                         
this Agreement shall be in writing, and mailed, telecopied or delivered by hand
delivery or by overnight courier service, to the parties at their respective
addresses as indicated below or at such other address as the parties may
designate in writing:

                    If to LCO:

                         LCO Investments Limited

                                       9
<PAGE>
 
                         Canada Court
                         Upland Road, St. Peter Port
                         Guernsey, Channel Islands

                         With a copy to:

                         Michael Yong
                         Cap Advisers Limited
                         36 Fitzwilliam Place
                         Dublin 2, Ireland
                         (Tel. 011-353-1-661-4433)
                         (Fax 011-353-1-661-2456)

                         Craigh Leonard
                         Richards & O'Neil, LLP
                         885 Third Avenue
                         New York, N.Y. 10022-4873
                         (Tel. 212-207-1200)
                         (Fax 212-750-9022)

                         Robert B. Hiden, Jr.
                         Sullivan & Cromwell
                         125 Broad Street
                         New York, N.Y. 10004
                         (Tel. 212-558-3812)
                         (Fax 212-558-4783)

                    If to the Company:

                         Ion Laser Technology, Inc.
                         3828 South Main Street
                         Salt Lake City, Utah 84115

                         With a copy to:

                         Durham, Evans, Jones & Pinegar
                         50 South Main, Suite 850
                         Salt Lake City, Utah 84144
                         Attn:  Jeffrey M. Jones, Esq.

All notices and communications shall be effective as follows:  When mailed, upon
three (3) business days after deposit in the mail (postage prepaid); when
telecopied, upon confirmed transmission of the telecopied notice; when hand
delivered, upon delivery; and when sent by overnight courier, the next business
day after deposit of the notice with the overnight courier.

                                       10
<PAGE>
 
          13.7 Remedies.  Any person having rights under any provision of this
               --------                                                       
Agreement will be entitled to enforce such rights specifically, to recover
damages caused by reason of any breach of any provision of this Agreement and to
exercise all other rights granted by law.


     DATED: May 4, 1998.


                    ION LASER TECHNOLOGY, INC., a Utah corporation


                         By     /s/ Milton G. Adair
                            -------------------------------------------
                                Milton G. Adair, President and CEO



                    LCO INVESTMENTS LIMITED


                         By     Anthony M. Pilaro
                            --------------------------------------------

                         Its    Chairman
                             -------------------------------------------

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