CONSENT AND LIMITED WAIVER

     THIS CONSENT AND LIMITED WAIVER (this  "Consent") is dated  effective as of
March 31, 2000, by David D. Dulany,  M.D.  ("Dulaney"),  Ronald W. Barnet,  M.D.
("Barnet"),  Mark Rosenberg ("Rosenberg"),  Barnet Dulaney Eye Center, P.L.L.C.,
an Arizona  professional  limited liability  company ("BDEC"),  LASIK Investors,
L.L.C.,  a Delaware  limited  liability  company  ("LASIK"),  Prime  Refractive,
L.L.C., a Delaware limited  liability  company ("Prime  Refractive"),  Prime/BDR
Acquisition,  L.L.C.,  a Delaware limited  liability  company ("Prime BDR"), and
Prime/BDEC  Acquisition,  L.L.C., a Delaware limited  liability  company ("Prime
BDEC" and together with all of the foregoing parties, the "Consenting  Parties")
for the benefit of Prime Medical Services, Inc., a Delaware corporation ("PMSI")
and each subsidiary and affiliate of PMSI.

         WHEREAS, the Consenting Parties, PMSI, Prime Medical Operating, Inc., a
Delaware  corporation,  and Prime  Refractive  Management,  L.L.C.,  a  Delaware
limited  liability  company are parties to that certain  Contribution  Agreement
(the  "Contribution  Agreement")  dated as of  September  1,  1999,  as  amended
pursuant to that certain First Amendment to  Contribution  Agreement dated as of
January 31, 2000;

         WHEREAS,  pursuant to Article VIII of the Contribution Agreement,  PMSI
is prohibited  from acquiring  another center engaged in Refractive  Surgery (as
defined in the Contribution Agreement) unless an exception enumerated in Article
VIII applies to such acquisition; and

         WHEREAS,  the  Consenting  Parties  desire to consent to, and waive any
claims they may have as a result of, the  acquisition  by PMSI  (through  one or
more of its subsidiaries or affiliates) of certain assets from Ken Moadel,  M.D.
(and  certain  entities  owned  or  controlled  by Ken  Moadel,  M.D.)  and  the
establishment of a Refractive  Surgery joint venture with Ken Moadel,  M.D. that
will engage in business  activities  similar to those  engaged in by Prime BDEC,
including  without  limitation,  the provision of services related to Refractive
Surgery (the "Moadel Acquisition").

         NOW,  THEREFORE,  in consideration of the agreements  herein contained,
the parties hereto agree as follows:

         1. Consent and Limited Waiver.  Each of the Consenting  Parties, on its
own  behalf  and on behalf of its  affiliates,  hereby  consents  to the  Moadel
Acquisition on whatever  terms and  conditions  agreed to by PMSI and waives any
present  or future  claim it may have or claim to have as a result of the Moadel
Acquisition.  Each of the  Consenting  Parties agrees that this Consent shall be
effective as of the date first written above, notwithstanding the actual date of
execution.

         2.  Miscellaneous.  The parties hereto agree that,  except as expressly
waived by this Consent,  none of the rights,  interests and obligations existing
and to exist under the Contribution Agreement are hereby released, diminished or
impaired, and the Contribution Agreement, and the exhibits thereto, shall remain
in full force and effect.  This  Consent  shall be governed by and  construed in
accordance with the laws of the State of Texas.

                            [Signature page follows]


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                                                    S-3

                                 SIGNATURE PAGE

                                       TO

                           CONSENT AND LIMITED WAIVER

         IN WTNESS  WHEREOF,  the parties  hereto  have  executed  this  Consent
effective as of the date first written above.

BDEC:                               Barnet Dulaney Eye CENTER, P.L.L.C.

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

LASIK:                              LASIK INVESTORS, L.L.C.


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

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

PRIME BDR:                          PRIME/BDR ACQUISITION, L.L.C.
                                            Ronald W. Barnet, M.D., signing as
                                            a manager of Prime BDR,and on behalf
                                            of LASIK as a
                                            member of Prime BDR



                                            David D. Dulaney, M.D., signing as a
                                            manager of Prime BDR, and on behalf
                                            of LASIK as a
                                            member of Prime BDR



                                            Teena Belcik, signing as a manager
                                            of Prime BDR, and on behalf of PMOI
                                            as a member of Prime BDR



PRIME BDEC:                         PRIME/BDEC ACQUISITION, L.L.C.

                                            Ronald W. Barnet, M.D., signing as a
                                            manager of Prime BDEC, and on behalf
                                            of LASIK as a member of Prime BDEC



                                            David D. Dulaney, M.D., signing as a
                                            manager of Prime BDEC, and on behalf
                                            of LASIK as a member of Prime BDEC



                                            Teena Belcik, signing as a manager
                                            of Prime BDEC, and on behalf of PMOI
                                            as a member of Prime BDEC



PRIME REFRACTIVE:          PRIME REFRACTIVE, L.L.C.

                                            Ronald W. Barnet, M.D., signing as a
                                            manager of Prime Refractive, and on
                                            behalf of LASIK
                                            as a member of Prime Refractive



                                            David D. Dulaney, M.D., signing as a
                                            manager of Prime Refractive, and on
                                            behalf of LASIK
                                            as a member of Prime Refractive



                                            Teena Belcik, signing as a manager
                                            of Prime Refractive, and on behalf
                                            of PMOI as a member
                                            of Prime Refractive



DULANEY:

                                            David D. Dulaney, M.D.



BARNET:

                                            Ronald W. Barnet, M.D.



ROSENBERG:

                                            Mark Rosenberg