LIMITED LIABILITY COMPANY AGREEMENT

                           OF PRIME REFRACTIVE, L.L.C.

     Organized under the Delaware Limited Liability Company Act (the "Act").

                                   ARTICLE I.

                                NAME AND LOCATION

     Section  1.1.  Name.  The name of this limited  liability  company is Prime
Refractive, L.L.C. (the "Company").

         Section  1.2.  Members.  The  only  members  of the  Company  upon  the
execution of this Limited Liability Company Agreement (this  "Agreement")  shall
be Prime Refractive  Management,  L.L.C., a Delaware limited  liability  company
("Prime  Management"),  and LASIK Investors L.L.C., a Delaware limited liability
company ("LASIK").  LASIK acknowledges and agrees that it initially owned all of
the outstanding  membership  interests of the Company and that Prime  Management
acquired its membership interest in the Company from LASIK. For purposes of this
Agreement,  the  "Members"  shall include such named members and any new members
admitted  pursuant  to the terms of this  Agreement,  but does not  include  any
person or entity who has ceased to be a member in the Company.

     Section 1.3. Principal Office. The principal office of the Company shall be
located in 1301 Capital of Texas Hwy., Suite C-300, Austin, Texas 78746-6550, or
such other location as may be selected by the Members.

     Section 1.4. Registered Agent and Address. The name of the registered agent
and the  address  of the  registered  office of the  Company as set forth in the
Certificate of Formation of the Company are:

                          The Corporation Trust Company
                          1209 Orange Street
                          Wilmington, Delaware 19801

     Section 1.5.  Other  Offices.  Other offices and other  facilities  for the
transaction of business shall be located at such places as the Managers may from
time to time determine.

         Section 1.6  Contribution  Agreement.  The Company was initially formed
with a single member, LASIK, in connection with the transactions contemplated by
that certain  Contribution  Agreement dated effective  September 1, 1999, by and
among Prime Medical  Operating,  Inc., a Delaware  corporation  ("PMOI"),  Prime
Medical Services,  Inc., a Delaware corporation ("PMSI"),  LASIK, Barnet Dulaney
Eye Center,  P.L.L.C.,  an Arizona  professional  limited liability company, the
Company, Prime Management,  Prime/BDEC  Acquisition,  L.L.C., a Delaware limited
liability company,  Prime/BDR Acquisition,  L.L.C., a Delaware limited liability
company,  David D. Dulaney, M.D., Ronald W. Barnet, M.D., and Mark Rosenberg (as
amended by that certain First  Amendment to  Contribution  Agreement dated as of
January 31, 2000, among the foregoing  parties,  the "Contribution  Agreement").
This agreement  supercedes and replaces any prior membership  agreement or other
governing or organizational document of the Company.

                                   ARTICLE II.

                                   MEMBERSHIP

     Section 2.1. Members' Interests.  The "Membership  Interest" of each Member
is set forth on Exhibit A.

     Section 2.2. Admission to Membership. The admission of new Members shall be
only by the unanimous  vote of the Members.  If new members are  admitted,  this
Agreement shall be amended to reflect each Member's revised Membership Interest.

     Section 2.3.  Property  Rights.  No Member shall have any right,  title, or
interest in any of the property or assets of the Company.

     Section  2.4.  Liability  of  Members.  No Member of the  Company  shall be
personally  liable for any debts,  liabilities,  or  obligations of the Company,
including under a judgment decree, or order of court.

         Section 2.5.  Transferability of Membership.  Except as provided below,
Membership  Interests in the Company are  transferable  only with the  unanimous
written  consent  of all  Members.  If such  unanimous  written  consent  is not
obtained when  required,  the  transferee  shall be entitled to receive only the
share of  profits  or other  compensation  by way of  income  and the  return of
contributions  to which  the  transferor  Member  otherwise  would be  entitled.
Notwithstanding the foregoing,  (i) the Membership Interests of Prime Management
may be freely transferred,  without consent, to any entity that is then owned or
controlled, directly or indirectly, by PMSI (or its successor in interest), (ii)
the  Membership  Interests  of any  Member  may be freely  assigned,  pledged or
otherwise  transferred,  without  consent,  to  secure  any debt,  liability  or
obligation owed to PMOI or its  subsidiaries  or affiliates by the Company,  any
Member or any entity affiliated with the Company, (iii) the Membership Interests
of any Member may be freely assigned, pledged or otherwise transferred,  without
consent, in favor of the Lender(s) under, or by the Lender(s) as a result of the
enforcement of any security  interest  arising  pursuant to, that certain Senior
Credit  Facility of PMSI (as  amended) or pursuant to that  certain  $14,000,000
Credit Facility of Prime Management (as amended),  (iv) the Membership Interests
of any Member may be freely  transferred,  without  consent,  pursuant to and in
accordance with the express terms and conditions of the Contribution  Agreement,
and (iv) the  pledge  by LASIK  (pursuant  to  Section  6.3 of the  Contribution
Agreement) of its right to receive  distributions from the Company in respect of
its  Membership  Interest  shall not be deemed to violate any  provision of this
Agreement..

         Section 2.6. Resignation of Members. A Member may not withdraw from the
Company except on the unanimous consent of the remaining  Members.  The terms of
the Members  withdrawal  shall be determined by agreement  between the remaining
Members and the withdrawing Member.

                                  ARTICLE III.

                                MEMBERS' MEETINGS

         Section  3.1.  Time and Place of Meeting.  All  meetings of the Members
shall be held at such  time and at such  place  within or  without  the State of
Delaware as shall be determined by the Managers.

         Section 3.2. Annual  Meetings.  In the absence of an earlier meeting at
such  time and place as the  Managers  shall  specify,  annual  meetings  of the
Members shall be held at the  principal  office of the Company on the date which
is thirty  (30) days after the end of the  Company's  fiscal year if not a legal
holiday,  and if a legal holiday,  then on the next full business day following,
at 10:00 a.m.,  at which  meeting the Members may transact  such business as may
properly be brought before the meeting.

     Section  3.3.  Special  Meetings.  Special  meetings  of the Members may be
called at any time by any Member.  Business transacted at special meetings shall
be confined to the purposes stated in the notice of the meeting.

         Section 3.4.  Notice.  Written or printed notice stating the place, day
and hour of any Members'  meeting,  and, in the case of a special  meeting,  the
purpose or purposes for which the meeting is called, shall be delivered not less
than ten (10) days nor more than thirty (30) days before the date of the special
meeting,  either  personally  or by mail,  by or at the  direction of the person
calling the meeting, to each Member entitled to vote at such meeting. If mailed,
such notice shall be deemed to be delivered three (3) days after it is deposited
in the United States mail,  postage prepaid,  to the Member at his address as it
appears on the records of the Company at the time of mailing.

         Section 3.5. Quorum. Members present in person or represented by proxy,
holding  more than fifty  percent  (50%) of the total votes which may be cast at
any meeting  shall  constitute  a quorum at all  meetings of the Members for the
transaction  of  business.  If,  however,  such  quorum  shall not be present or
represented at any meeting of the Members, the Members entitled to vote, present
in person or represented by proxy,  shall have power to adjourn the meeting from
time to time,  without notice other than  announcement  at the meeting,  until a
quorum shall be present or represented. When any adjourned meeting is reconvened
and a quorum shall be present or  represented,  any  business may be  transacted
which might have been  transacted at the meeting as originally  noticed.  Once a
quorum is constituted,  the Members present or represented by proxy at a meeting
may  continue  to  transact  business  until  adjournment,  notwithstanding  the
subsequent  withdrawal therefrom of such number of Members as to leave less than
a quorum.

         Section 3.6. Voting. When a quorum is present at any meeting,  the vote
of the Members, whether present or represented by proxy at such meeting, holding
more  than  fifty  percent  (50%) of the  total  votes  which may be cast at any
meeting shall be the act of the Members,  unless the vote of a different  number
is required by the Act, the  Certificate of Formation or this Limited  Liability
Company Agreement. Each Member shall be entitled to one vote for each percentage
point  represented by their  Membership  Interest.  Fractional  percentage point
interests shall be entitled to a corresponding fractional vote.

         Section  3.7.  Proxy.  Every  proxy must be  executed in writing by the
Member or by his duly authorized  attorney-in-fact,  and shall be filed with the
Secretary of the Company prior to or at the time of the meeting.  No proxy shall
be  valid  after  eleven  (11)  months  from the  date of its  execution  unless
otherwise  provided  therein.  Each proxy shall be  revocable  unless  expressly
provided therein to be irrevocable and unless otherwise made irrevocable by law.

         Section  3.8.  Action  by  Written  Consent.  Any  action  required  or
permitted  to be taken at any  meeting  of the  Members  may be taken  without a
meeting if a consent in  writing,  setting  forth the action so taken,  shall be
signed by all of the Members entitled to vote with respect to the subject matter
thereof,  and such  consent  shall have the same force and effect as a unanimous
vote of Members.

         Section 3.9. Meetings by Conference Telephone.  Members may participate
in and hold  meetings  of Members by means of  conference  telephone  or similar
communications  equipment  by means of which all  persons  participating  in the
meeting  can  hear  each  other,  and  participation  in  such a  meeting  shall
constitute   presence  in  person  at  such  meeting,   except  where  a  person
participates  in the  meeting  for  the  express  purpose  of  objecting  to the
transaction  of any  business  on the ground  that the  meeting is not  lawfully
called or convened.

                                   ARTICLE IV.

                        MEMBERSHIP CAPITAL CONTRIBUTIONS

         Except  for  each  Member's  initial  capital   contribution   made  in
connection with the formation of the Company, no capital  contributions shall be
required  of any  Member  without  the  approval  of all the  Members  to  raise
additional capital, and only then proportionately as to each Member.

                                   ARTICLE V.

                             DISTRIBUTION TO MEMBERS

         The Company shall not  distribute (or allow to be  distributed)  to its
members,  with respect to their  respective  membership  interests,  any cash or
other  property  of the  Company  or its  subsidiaries  if,  at the  time of the
proposed   distribution,   any  amounts  (whether  principal  or  interest)  are
outstanding  under the Credit  Documents or the Target Center Lending  Documents
(as such terms are  defined in the  Contribution  Agreement).  Furthermore,  the
Company  shall  pay  all  available  cash  flow  in  payment  of  the  Company's
outstanding obligations,  if any, under the Working Capital Line and Development
Facility (as such terms are defined in the Contribution Agreement), irrespective
of whether such payments exceed the minimum required  payments under the Working
Capital Line and Development Facility.  For purposes of allocating such payments
among any two or more of such  outstanding  obligations,  such payments shall be
allocated  pro rata,  based upon the  respective  balances of such  obligations,
unless (i) a greater  portion of the  payment is  required  to be paid  toward a
given  obligation in order to prevent a default with respect to that  obligation
(but only to the extent  necessary  to prevent  such a default)  or (ii)  eighty
percent (80%) of the managers of the Company elect to allocate the payments in a
different manner.

         Notwithstanding  the foregoing,  as long as no party other than PMSI or
PMOI is in default  under the  Contribution  Agreement or any other  Transaction
Document (as defined in the Contribution Agreement, but excluding,  however, the
Credit Documents and the Target Center Lending  Documents),  then, to the extent
that (but only to the extent that) the Company possesses the cash flow necessary
(in  the  reasonable  discretion  of a  majority  of its  managers)  to pay  its
liabilities in the ordinary course  consistent with past practices,  the Company
agrees to make  quarterly  estimates  of its taxable  income for the current tax
year  and,  if not  prohibited  by law,  distribute  quarterly  (the  "Quarterly
Distributions")  an amount that would cover the federal and state  income  taxes
required to be paid by its members with respect  such taxable  income,  based on
each member's then current proportionate interest in the Company,  assuming that
all members pay income taxes on the Company's  taxable  earnings at a rate equal
to the highest  effective  individual  tax rate in effect from time to time (the
"Assumed Tax Rate");  provided,  further,  that the Company shall  determine its
actual  taxable  income at the end of each taxable year and (A) if the Quarterly
Distributions  in a given year should  have been  higher  based on the amount of
actual taxable income for that year,  promptly  distribute the amounts necessary
to eliminate such  deficiency or (B) if the Quarterly  Distributions  in a given
year  should have been lower  based on the amount of actual  taxable  income for
that  year,  withhold  dollar  for  dollar  from the first  following  Quarterly
Distribution,  and then against  subsequent  Quarterly  Distributions  in a like
manner, the amounts necessary to eliminate such surplus.

         Subject to the foregoing,  the Managers shall determine,  in their sole
discretion,  the  amount  and  timing  of all  distributions  from the  Company.
Distributions  shall be  divided  among the  Members  in  accordance  with their
Membership Interests. Distributions in kind shall be made on the basis of agreed
value  as  determined  by the  Members.  In no  event  may  the  Company  make a
distribution  to  its  Members  if,  immediately  after  giving  effect  to  the
distribution,  all  liabilities  of the Company,  other than  liabilities to the
Members with respect to their  interests and  liabilities for which the recourse
of creditors is limited to  specified  property of the Company,  exceed the fair
value of the  Company's  assets;  except that the fair value of property that is
subject to  liability  for which  recourse of  creditors  is  limited,  shall be
included  in the  Company  assets  only to the extent that the fair value of the
property  exceeds that  liability.  Except as contemplated in this Article V, no
distributions  of cash or  other  assets  of the  Company  shall  be made to the
Members in their capacity as owners of the Company.

                                   ARTICLE VI.

              ALLOCATION OF NET PROFITS AND LOSSES FOR TAX PURPOSES

         For  accounting  and income tax  purposes,  all items of income,  gain,
loss,  deduction,  and  credit of the  Company  for any  taxable  year  shall be
allocated  among the  Members in  accordance  with their  respective  Membership
Interests,  except as may be otherwise  required by the Internal Revenue Code of
1986, as amended.

                                  ARTICLE VII.

                           DISSOLUTION AND WINDING UP

     Section 7.1.  Dissolution.  Notwithstanding  any  provision of the Act, the
Company shall be dissolved only upon the first of the following to occur:

               (a) Forty (40) years from the date of filing the  Certificate  of
          Formation of the Company;

               (b)  Written   consent  of  all  the  then  current   Members  to
          dissolution;

                  (c) The  bankruptcy of a Member,  unless there is at least one
         remaining Member and such Member or, if more than one remaining Member,
         all remaining Members agree to continue the Company and its business.

         Section 7.2.  Winding Up.  Unless the Company is continued  pursuant to
Section 7.1(c) of this Article VII., in the event of dissolution of the Company,
the Managers (excluding any Manager(s) holding office pursuant to designation by
a Member subject to bankruptcy  proceedings) shall wind up the Company's affairs
as soon  as  reasonably  practicable.  On the  winding  up of the  Company,  the
Managers  shall pay and/or  transfer the assets of the Company in the  following
order:

               (a) In discharging liabilities (including loans from Members) and
          the expenses of concluding the Company's affairs; and

               (b) The balance,  if any, shall be divided between the Members in
          accordance with the Members' Membership Interests.

                                  ARTICLE VIII.

                                    MANAGERS

         Section 8.1. Selection of Managers.  Management of the Company shall be
vested in the  Managers.  Initially,  the Company  shall have five (5) Managers,
being Ken  Shifrin,  Teena  Belcik,  and Brad  Hummel,  (as the initial  Manager
designees of Prime  Management),  David D. Dulaney,  M.D., and Ronald W. Barnet,
M.D. (as the initial  Manager  designees of LASIK).  Thereafter,  for so long as
there are five (5) Managers, (a) Prime Management shall be entitled to designate
three (3) of the  Managers;  and (b) LASIK shall be entitled  to  designate  the
remaining two (2) of the Managers. Notwithstanding the foregoing, a Member shall
not be entitled to designate any Manager unless its Membership Interest: (x) has
not  (other  than  as  allowed  under  Section  2.5  of  this   Agreement)  been
transferred,   repurchased,  assigned,  pledged,  hypothecated  or  in  any  way
alienated;  and (y)  equals or  exceeds  forty  percent  (40%) of the  aggregate
Membership  Interests;  provided,  however,  that if the  immediately  preceding
subsection  (y) shall apply to LASIK  solely  because of an exercise by LASIK of
its put rights  under  Section  9.8 of the  Contribution  Agreement,  then LASIK
shall,  unless  and  until  there is an  additional  decrease  in it  Membership
Interest other than pursuant to Section 9.8 of the  Contribution  Agreement,  be
entitled to designate only one Manager in the manner provided above. The Members
may, by unanimous vote of all Members,  from time to time,  change the number of
Managers of the Company and remove or add Managers accordingly.  A Manager shall
serve as a Manager until their resignation or removal pursuant to Section 8.2 or
8.3 of this  Article  VIII.  Managers  need  not be  residents  of the  State of
Delaware or Members of the Company.

         Section 8.2. Resignations.  Each Manager shall have the right to resign
at any time upon  written  notice of such  resignation  to the  Members.  Unless
otherwise  specified in such written notice,  the resignation  shall take effect
upon the  receipt  thereof,  and  acceptance  of such  resignation  shall not be
necessary to make same effective.  The Member who designated a resigning manager
shall be entitled to designate  the  successor  thereto and all Members agree to
take such action as may be necessary to cause the election of all such successor
Managers.

         Section 8.3.  Removal of Managers.  Any Manager may be removed,  for or
without cause,  at any time, but only by the Member who designated such Manager,
upon the written notice to all Members.  The Member who designated  such removed
Manager  shall be entitled to designate  the  successor  thereto and all Members
agree to take such action as may be  necessary to cause the election of all such
successor Managers.

         Section  8.4.  General  Powers.  The  business of the Company  shall be
managed by its Managers, which may, by the vote or written consent in accordance
with this  Agreement,  exercise any and all powers of the Company and do any and
all such  lawful  acts and  things  as are not by the Act,  the  Certificate  of
Formation or this Limited Liability Company Agreement directed or required to be
exercised or done by the Members, including, but not limited to, contracting for
or incurring on behalf of the Company debts,  liabilities and other obligations,
without the consent of any other person, except as otherwise provided herein.

     Section 8.5. Place of Meetings.  The Managers of the Company may hold their
meetings,  both  regular  and  special,  either  within or without  the State of
Delaware.

         Section 8.6. Annual Meetings.  The annual meeting of the Managers shall
be held without further notice  immediately  following the annual meeting of the
Members, and at the same place, unless by unanimous consent of the Managers that
such time or place shall be changed.

     Section 8.7. Regular Meetings. Regular meetings of the Managers may be held
without  notice at such time and place as shall from time to time be  determined
by the Managers.

     Section  8.8.  Special  Meetings.  Special  meetings  of the Mangers may be
called by any Manager on seven (7) days notice to each Manager, with such notice
to be given personally, by mail or by telecopy, telegraph or mailgram.

         Section  8.9.  Quorum and Voting.  At all  meetings of the Managers the
presence of at least four (4) Managers  shall be  necessary  and  sufficient  to
constitute a quorum for the transaction of business, and the affirmative vote of
at least a majority of the  Managers  present at any meeting at which there is a
quorum shall be the act of the Managers, except as may be otherwise specifically
provided by the Act, the Contribution Agreement, the Certificate of Formation or
this Agreement. If a quorum shall not be present at any meeting of Managers, the
Managers  present there may adjourn the meeting from time to time without notice
other  than  announcement  at the  meeting,  until a quorum  shall  be  present.
Notwithstanding any voting, quorum, or other provisions of this Agreement to the
contrary,  the affirmative  vote of at least four (4) Managers shall be required
to effect any of the following actions:

               (a) any amendment, modification or waiver of any provision of the
          Company's Certificate of Formation or this Agreement;

               (b) effecting any mergers,  consolidations or combinations of the
          Company with other entities;

               (c)  dissolving,  liquidating,  or filing  bankruptcy  or seeking
          relief under any debtor relief law;

               (d) entering into a transaction  or other action with a Member or
          Manager;

                  (e) borrowing or incurring any  indebtedness,  other than open
         accounts  payable  to  unaffiliated  third  parties,  or  granting  any
         collateral  or  security  (by way of  guaranty  or  otherwise)  for any
         indebtedness or obligation,  that exceeds (in any single transaction or
         directly related series of transactions) $25,000;

                  (f) purchasing or leasing assets or property, or entering into
         any  contract  or  obligation,  which  obligates  the Company to pay in
         excess  of  $25,000  in  one  or  any   directly   related   series  of
         installments;

               (g) selling, leasing or otherwise transferring  substantially all
          of the  Company's  assets  other  than in the  ordinary  course of the
          Company's business;

                  (h)  except  as  expressly  set forth in  Section  9.12 of the
         Contribution Agreement, allocating to the Company any costs or expenses
         that are paid or  incurred by any Member or its  affiliates  (excluding
         the Company),  or paid by the Company but reimbursable by any Member or
         its affiliates (excluding the Company), in each instance;

               (i) issuance of any ownership interest in the Company; and

                  (j)  disposition,  sale,  assignment or other  transfer by the
         Company  of any  interest  it owns in the  Company,  except  that  such
         interest may be extinguished  without the approval  required under this
         Section.

         Section 8.10.  Committees.  The Managers  may, by resolution  passed by
eighty percent (80%) of the Managers,  designate  committees,  each committee to
consist  of two or more  Managers  (at  least  one of  which  must be a  Manager
designee  of Prime  Management  and one of which must be a Manager  designee  of
LASIK),  which  committees shall have such power and authority and shall perform
such  functions  as may be  provided  in  such  resolution.  Such  committee  or
committees  shall have such name or names as may be  designated  by the Managers
and shall keep regular  minutes of their  proceedings and report the same to the
Managers when required.

         Section  8.11.  Compensation  of Managers.  The Members  shall have the
authority  to  provide,  by  unanimous  approval,  that  any  one or more of the
Managers  shall not be  compensated,  and may, by  unanimous  approval,  fix any
compensation  (which may include  expenses) they elect to pay to any one or more
of the Managers.

         Section  8.12.  Action by  Written  Consent.  Any  action  required  or
permitted  to be  taken  at any  meeting  of the  Managers  or of any  committee
designated  by the Managers may be taken  without a meeting if written  consent,
setting  forth the  action so taken,  is signed by all the  Managers  or of such
committee,  and such consent shall have the same force and effect as a unanimous
vote at a meeting.

         Section 8.13. Meetings by Conference Telephone.  Managers or members of
any committee  designated by the Managers may  participate in and hold a meeting
of the Managers or such  committee by means of  conference  telephone or similar
communications  equipment  by means of which all  persons  participating  in the
meeting  can  hear  each  other,  and  participation  in  such a  meeting  shall
constitute   presence  in  person  at  such  meeting,   except  where  a  person
participates  in the  meeting  for  the  express  purpose  of  objecting  to the
transaction  of any  business  on the ground  that the  meeting is not  lawfully
called or convened.

     Section  8.14.  Liability of Managers.  No Manager of the Company  shall be
personally  liable for any debts,  liabilities,  or  obligations of the Company,
including under a judgment, decree, or order of the court.

         Section 8.15.  Specific Power of Managers.  The Managers shall have the
authority to enter into and execute all  documents in relation to the  formation
of the Company  including,  but not limited to,  issuance of the  Certificate of
Formation and this Limited Liability Company Agreement.

                                   ARTICLE IX.

                                     NOTICES

         Section 9.1. Form of Notice.  Whenever under the provisions of the Act,
the Certificate of Formation or this Limited  Liability Company Agreement notice
is required to be given to any Manager or Member, and no provision is made as to
how such notice shall be given,  notice shall not be construed to mean  personal
notice only, but any such notice may also be given in writing,  by mail, postage
prepaid,  addressed  to such Manager or Member at such address as appears on the
books of the Company, or by telecopy, telegraph or mailgram. Any notice required
or  permitted  to be given by mail  shall be deemed  to be given  three (3) days
after it is deposited, postage prepaid, in the United States mail as aforesaid.

         Section 9.2. Waiver. Whenever any notice is required to be given to any
Manager or Member of the Company under the provision of the Act, the Certificate
of Formation or this Limited  Liability Company  Agreement,  a waiver thereof in
writing signed by the person or persons entitled to such notice,  whether signed
before or after the time stated in such waiver,  shall be deemed  equivalent  to
the giving of such notice.

                                   ARTICLE X.

                                    OFFICERS

         Any Manager may also serve as an officer of the  Company.  The Managers
may  designate  one or more persons who are not Managers of the Company to serve
as officers and may designate the titles of all officers.  The initial  officers
of the Company shall be: Ken Shifrin,  Chairman of the Board; Joe Jenkins, M.D.,
President;  Cheryl  Williams,  Vice  President,  Secretary  and Chief  Financial
Officer;  and Mark Rosenberg,  Vice President.  Unless  otherwise  provided in a
resolution of the Members or Managers the officers of the Company shall have the
powers  designated  with  respect to such  offices  under the  Delaware  Limited
Liability Company Act, and any successor statute, as amended from time-to-time.

                                   ARTICLE XI.

                                    INDEMNITY

         Section 11.1.  Indemnification.  The Company shall indemnify any person
who was or is a party or is  threatened  to be made a party  to any  threatened,
pending or  completed  action,  suit or  proceeding,  whether  civil,  criminal,
administrative, arbitrative or investigative, any appeal in such an action, suit
or  proceeding  and any  inquiry  or  investigation  that  could lead to such an
action,  suit or proceeding  (whether or not by or in the right of the Company),
by reason of the fact that such person is or was a manager, officer, employee or
agent of the  Company or is or was  serving at the  request of the  Company as a
director,  manager, officer, partner, venturer,  proprietor,  trustee, employee,
agent or similar  functionary  of another  corporation,  employee  benefit plan,
other enterprise,  or other entity, against all judgments,  penalties (including
excise and similar taxes), fines, settlements and reasonable expenses (including
attorneys'  fees and court  costs)  actually and  reasonably  incurred by him in
connection with such action,  suit or proceeding to the fullest extent permitted
by any  applicable  law,  and such  indemnity  shall inure to the benefit of the
heirs,  executors and administrators of any such person so indemnified  pursuant
to this Article XI. The right to indemnification  under this Article XI shall be
a contract  right and shall not be deemed  exclusive of any other right to which
those seeking  indemnification may be entitled under any law, bylaw,  agreement,
vote of members or disinterested managers or otherwise, both as to action in his
official  capacity  and as to action in  another  capacity  while  holding  such
office. Any repeal or amendment of this Article XI by the Members of the Company
or by changes in  applicable  law shall,  to the extent  permitted by applicable
law, be prospective only, and shall not adversely affect the  indemnification of
any person who may be indemnified at the time of such repeal or amendment.

         Section   11.2.   Indemnification   Not   Exclusive.   The   rights  of
indemnification  and reimbursement  provided for in this Article XI shall not be
deemed  exclusive  of any  other  rights  to which  any such  Manager,  officer,
employee or agent may be  entitled  under the  Certificate  of  Formation,  this
Limited  Liability  Company  Agreement,  agreement  or vote of Members,  or as a
matter of law or otherwise.

         Section  11.3.  Other  Indemnification  Clauses.   Notwithstanding  the
foregoing,   this  Article  XI  shall  not  be  construed  to   contradict   the
indemnification   provision  of  the  Contribution  Agreement.   Notwithstanding
anything  contained  herein,  this Article XI shall be ineffectual and shall not
permit or require  indemnification for all, or any, losses, costs,  liabilities,
claims or expenses arising, directly or indirectly,  from any action or omission
permitting or requiring indemnification under the Contribution Agreement; and in
no event may any  indemnity be allowed  under this  Agreement or pursuant to any
provision   of  the  Act  for  an  amount  paid  or  payable   pursuant  to  the
indemnification provisions of the Contribution Agreement.

                                  ARTICLE XII.

                                  MISCELLANEOUS

     Section 12.1. Fiscal Year. The fiscal year of the Company shall be fixed by
resolution of the Managers.

     Section 12.2.  Records.  At the expense of the Company,  the Managers shall
maintain  records and accounts of all  operations of the Company.  At a minimum,
the Company shall keep at its principal place of business the following records:

               (a) A current list of the name and last known mailing  address of
          each Member;

               (b) A current list of each Member's Membership Interest;

               (c) A copy of the Certificate of Formation and Limited  Liability
          Company Agreement of the Company, and all amendments thereto, together
          with executed copies of any powers of attorney;

               (d) Copies of the  Federal,  state,  and local income tax returns
          and reports for the Company's six most recent tax years; and

               (e)  Correct  and  complete  books and  records of account of the
          Company.

         Section 12.3. Seal. The Company may by resolution of the Managers adopt
and have a seal, and said seal may be used by causing it or a facsimile  thereof
to be  impressed  or  affixed or in any manner  reproduced.  Any  officer of the
Company shall have authority to affix the seal to any document requiring it.

     Section 12.4. Agents.  Every Manager and Officer is an agent of the Company
for the purpose of the business. The act of a Manager or Officer,  including the
execution  in the name of the Company of any  instrument  for carrying on in the
usual way the business of the Company, binds the Company.

         Section 12.5. Checks. All checks,  drafts and orders for the payment of
money,  notes  and other  evidences  of  indebtedness  issued in the name of the
Company  shall be  signed  by such  officer,  officers,  agent or  agents of the
Company  and in such  manner  as  shall  from  time to  time  be  determined  by
resolution of the Managers. In the absence of such determination by the Mangers,
such  instruments  shall  be  signed  by  the  Treasurer  or the  Secretary  and
countersigned  by the  President  or a Vice  President  of the  Company,  if the
Company has such officers.

     Section 12.6.  Deposits.  All funds of the Company shall be deposited  from
time to time to the credit of the  Company in such  banks,  trust  companies  or
other depositories as the Managers may select.

         Section  12.7.  Annual  Statement.  The Managers  shall present at each
annual  meeting,  and,  when called for by vote of the  Members,  at any special
meeting of the Members, a full and clear statement of the business and condition
of the Company.

         Section 12.8.  Financial  Statements.  As soon as practicable after the
end of each fiscal year of the  Company,  a balance  sheet as at the end of such
fiscal year,  and a profit and loss  statement  for the period  ended,  shall be
distributed  to the  Members,  along with such tax  information  (including  all
information  returns) as may be necessary for the  preparation of each Member of
its Federal,  state and local income tax returns.  The balance  sheet and profit
and loss statement  referred to in the previous  sentence may be as shown on the
Company's federal income tax return.

         Section 12.9. Binding Arbitration.  Any controversy between the parties
regarding  this  Agreement and any claims  arising out of this  Agreement or its
breach  shall be submitted  to  arbitration  by either  party.  The  arbitration
proceedings shall be conducted by a single arbitrator pursuant to the Commercial
Arbitration Rules of the American Arbitration Association. The arbitration shall
be conducted in Dallas,  Texas and the arbitrator  shall have the right to award
actual  damages  and  attorney  fees and costs,  but shall not have the right to
award punitive, exemplary or consequential damages against either party.

                                  ARTICLE XIII.

                                   AMENDMENTS

         Section 13.1.  Amendments.  This  Agreement may be altered,  amended or
repealed and a new limited liability  company agreement may be adopted,  only in
accordance  with the  provisions  of Section 8.9,  but  otherwise at any regular
meeting or at any special meeting called for that purpose,  or by execution of a
written consent in accordance with the provisions of Section 3.8.

         Section 13.2. When Limited  Liability  Company  Agreement Silent. It is
expressly recognized that when the Limited Liability Company Agreement is silent
or in conflict with the  requirements  of the Act as to the manner of performing
any Company function, the provisions of the Act shall control.

                            [Signature page follows]


<PAGE>

                                SIGNATURE PAGE TO

                       LIMITED LIABILITY COMPANY AGREEMENT

         IN WITNESS WHEREOF,  the undersigned  Members hereby adopt this Limited
Liability  Company  Agreement as the Limited  Liability Company Agreement of the
Company, effective as of the 1st day of September, 1999.

                                           LASIK Investors, L.L.C.

                                           By: /s/ Ronald W. Barnet, M.D.
                                                 Ronald W. Barnet, M.D., manager

                                           By: /s/ David D. Dulaney, M.D.
                                                 David D. Dulaney, M.D., manager



                                           Prime Refractive Management, L.L.C.

                                           By: /s/ Cheryl Williams

                                           Printed Name: Cheryl Williams
                                           Title: Chief Financial Officer


<PAGE>
                                    EXHIBIT A

                               OWNERSHIP INTERESTS


Name                                                       Ownership Percentage

Prime Management                                                 60%

LASIK                                                            40%