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                    AGREEMENT TO AMEND AND EXTEND LEASE # 2
              TO LEASE DATED JANUARY 26. 1994, BY AND BETWEEN
        WELSH COMPANIES, INC.. AS AGENT FOR PRAEDIUM LAKE REALTY, LLC
        AS LANDLORD AND BMC INDUSTRIES. INC.. A MINNESOTA CORPORATION,
                                    AS TENANT


     THIS AMENDMENT TO LEASE, entered into and made as of the day of 23rd day of
January, 1997, by and between Welsh Companies, Inc., as agent for Praedium Lake
Realty, LLC, as Landlord and BMC Industries, Inc., as Tenant.


                                  WITNESSETH :

     WHEREAS, Landlord and Tenant have heretofore entered into a certain lease,
dated JANUARY 26, 1994 (the "Lease"), of a certain space at SUITE 312. 7100
NORTHLAND CIRCLE, MINNEAPOLIS, MINNESOTA (the "Leased Premises"), upon terms and
conditions described in said Lease; and

     WHERE, Landlord and tenant desire to amend said Lease as described below:

     NOW THEREFORE, in consideration of the rents reserved and of the covenants
and agreements herein set forth, it is agreed that the Lease be hereby amended
from and after January 1, 1997.

     1.   The term of the Lease is hereby extended for a period of  twenty-one
          (21) months and 16 days commencing on the last day of the initial term
          of the Lease and expiring on the last day of December, 2000.

     2.   The existing Leased Premises shall be increased from 6,038 square feet
          by 2,003 square feet (Suite 310) for a total of 8,041 square feet of
          net rentable area shown highlighted on the attached Exhibit A of Lease
          Amendment #2.

     3.   The Tenant's proportionate share of operating expenses shall be
          increased from 6,038 square feet to 8,041 square feet in accordance
          with the increase in square footage of the Leased Premises from and
          after January 1, 1997.

     4.   Base rent for Suite 310 (2,003 square feet) shall be $1,627.44 per
          month, from and after January 1, 1997, through the term of this
          Lease extension, December 31, 2000. The base rent for the original
          Leased Premises shall increase from $4,360.00 per month to $4,905.88
          per month from March 14, 1999, through the term of this Lease
          extension December 31, 2000.

     5.   Tenant Improvements: Landlord shall construct improvements at
          Landlord's sole cost per Exhibit B of Lease Amendment #2 attached
          hereto. Any additional improvements or modifications will be the
          Tenant's obligation and expense. Improvement  allowances for Suite 310
          are certified to be comparable to existing finishes in existing Suite
          312.

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     6.   In addition to the terms and conditions of Section 8, Personal
          Property Risk of the Lease  dated January 26, 1994, Tenant agrees to
          the following changes in policy protection and  agrees to purchase, in
          advance, and to carry in full force and effect, adequate insurance
          with a carrier acceptable to Landlord including at a minimum the
          following insurance:

          a.   "All Risk" fire and casualty insurance, including endorsements 
                for extended coverage, vandalism and malicious mischief, and 
                water damage covering the full replacement value of all of 
                Tenant's fixtures and personal property owned by Tenant that 
                Tenant has a right to remove from the Leased Premises at the 
                termination of the Lease.

          b.    Liability Insurance covering all acts of Tenant, within the
                Leased Premises and the Building in a total combined single
                limit coverage amount of not less than $1,000,000 for
                personal injury, death and property damage.

          c.    Such insurance policies shall, unless Landlord shall
                otherwise agree, include a waiver of subrogation
                endorsement.

     7.   In the event the Premises becomes available and ready for occupancy
          prior to the Commencement Date, Landlord may elect to permit Tenant to
          take occupancy of all or  part of the Premises prior to such date. In
          such event, it is agreed that such occupancy by Tenant shall be upon
          all of the terms and conditions here of except that base rent and
          operating expenses shall not be charged prior to January 1, 1997 for
          the expansion space of Suite 310.

     Except as is hereinabove set forth, all terms, provisions, and covenants of
the Lease shall remain unchanged and in full force and effect.

     IN WITNESS WHEREOF, the parties hereto have executed this Amendment as 
of the date and year first above written.

TENANT:

BMC Industries, Inc.
(A Minnesota Corporation)

By:            /s/ Michael P. Hawks     
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Its:      VP Finance and Administration, CFO    
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LANDLORD:

Welsh Companies, Inc., as agent for Praedium
Lake Realty, LLC

By:           /s/ Edward B. Chapman         
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                  Edward B. Chapman
Its:                Vice President              
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