<PAGE>   1
                                                                    EXHIBIT 10.1


                             PICTURETEL CORPORATION

                      NON-STATUTORY STOCK OPTION AGREEMENT


         1.       GRANT OF OPTION.

         PictureTel Corporation, a Delaware corporation (the "Company"), hereby
grants to Vinay Kumar (the "Executive"), an option to purchase an aggregate of
100,000 shares of authorized but not issued Common Stock of the Company, $.01
par value ("Common Stock") (hereinafter referred to as the "Option"), at a price
of $6.938 per share, purchasable as set forth in and subject to the terms and
conditions of this Stock Option Agreement (the "Agreement"). The Option is
intended to be a non-statutory stock option and the purchase price of the Option
is 100% of the fair market value per share of the Common Stock on the Grant
Date. The date of grant of this Option is January 4, 1999 (hereinafter referred
to as the "Grant Date") and the date ending twelve (12) months thereafter and
each subsequent three (3) month period thereafter is hereinafter referred to as
"First Exercise Date", "Second Exercise Date", "Third Exercise Date", etc.

         In granting this Option, the Committee has determined that the Option
will advance the interests of PictureTel Corporation by enhancing its ability to
(a) attract and retain an executive who is in a position to make significant
contributions to the success of the Company and its subsidiaries and (b)
encourage this executive to take into account the long-term interests of the
Company through ownership of shares of the Company's Common Stock ("Stock").

         2.       EXERCISE OF OPTION AND PROVISIONS FOR TERMINATION.

         (a)      EXERCISE SCHEDULE.

         Except as otherwise provided in this Agreement, this Option may be
exercised during the period ending ten (10) years after the Grant Date
(hereinafter the "Expiration Date"), on a cumulative basis as described below,
in installments as to not more than the following percentage of the shares
covered by this option during the respective installment periods set forth
below:

<TABLE>
<CAPTION>
                                                                                      Percentage (Number)
                                                                                           of Option
                      Exercise Period                                                 Shares Exercisable
                      ---------------                                                 ------------------
<S>                                                                                   <C>         <C>

On and After the Grant Date and Prior to the First Exercise Date                              None
On and After the First Exercise Date and Prior to the Second Exercise Date            25.00%      (25,000)
On and After the Second Exercise Date and Prior to the Third Exercise Date            31.25%      (31,250)
On and After the Third Exercise Date and Prior to the Fourth Exercise Date            37.50%      (37,500)
On and After the Fourth Exercise Date and Prior to the Fifth Exercise Date            43.75%      (43,750)
On and After the Fifth Exercise Date and Prior to the Sixth Exercise Date             50.00%      (50,000)
On and After the Sixth Exercise Date and Prior to the Seventh Exercise Date           56.25%      (56,250)
On and After the Seventh Exercise Date and Prior to the Eighth Exercise Date          62.50%      (62,500)
On and After the Eighth Exercise Date and Prior to the Ninth Exercise Date            68.75%      (68,750)
On and After the Ninth Exercise Date and Prior to the Tenth Exercise Date             75.00%      (75,000)
On and After the Tenth Exercise Date and Prior to the Eleventh Exercise Date          81.25%      (81,250)
On and After the Eleventh Exercise Date and Prior to the Twelfth Date                 87.50%      (87,500)
On and After the Twelfth Exercise Date and Prior to the Thirteenth Exercise Date      93.75%      (93,750)
On and After the Thirteenth Exercise Date                                            100.00%     (100,000)

</TABLE>

         The right of exercise shall be cumulative so that if the Option is not
exercised to the maximum extent permissible during any exercise period it shall
be exercisable, in whole or in part, with respect to all shares not so purchased
at any time prior to the Expiration Date or the earlier termination of this
option. This Option may not be exercised at any time after the Expiration Date.

         (b)      EXERCISE PROCEDURE.

         Subject to the conditions set forth in this Agreement, this option
shall be exercised by the Executive's delivery of written notice of exercise to
the Company, specifying the Option Grant Date, number of shares to be


<PAGE>   2
purchased, and the purchase price to be paid therefor and accompanied by payment
in full in accordance with Section 3. below. Such exercise shall be effective
upon receipt by the Company of such written notice together with the required
payment. The Executive may purchase less than the total number of shares covered
hereby, provided that no partial exercise of this option may be for any
fractional share or for less than ten whole shares.

         (c)      CONTINUOUS EMPLOYMENT REQUIRED.

         Except as otherwise provided in this Section 2., this option may not be
exercised unless the Executive, at the time he exercises this Option, is, and
has been at all times since the Grant Date of this Option, an employee of one or
more of the Company or a Subsidiary. A "Subsidiary" for purposes of this Option
shall be a corporation in which the Company owns directly or indirectly, stock
possessing fifty (50) percent of the total combined voting power of all classes
of stock. If this Option shall be assumed or a new option substituted therefor
in a transaction to which Section 425(a) of the Internal Revenue Code of 1986,
as amended (the "Code") applies, employment by such assuming or substituting
corporation (hereinafter called the "Successor Corporation") or a Subsidiary
thereof (but with the Successor Corporation substituted for the Company) shall
be considered for all purposes of this Option to be employment by the Company or
a Subsidiary, as the case may be.

         (d)      VOLUNTARY TERMINATION OF EMPLOYMENT.

         If the Executive voluntarily ceases to be employed by the Company or
Subsidiary, the right to exercise this Option shall terminate three (3) months
after such cessation (but in no event after the Expiration Date), PROVIDED that
this Option shall then be exercisable only to the extent that the Executive was
entitled to exercise this option on the date of such cessation.

         (e)      TERMINATION UPON DEATH OR DISABILITY.

         If the Executive dies or becomes disabled (within the meaning of
Section 105(d) (4) of the Code) prior to the Expiration Date, while he is in the
employ of the Company or a Subsidiary, this Option shall have the exercise
rights thereto accelerated so that for each full year of service with the
Company prior thereto, no less than twenty-five (25) percent of the aggregate
number of options covered hereby and not yet exercisable shall thereupon become
exercisable as of the termination date (not to exceed one hundred (100) percent
of the aggregate number of shares); all unexercised options for shares not
accelerated under the foregoing formula shall terminate as of the termination
day. All options that are exercisable after giving effect to the foregoing will
remain exercisable until one year following the date of death or disability of
the Executive (but in no event after the Expiration Date) by the Employee or by
the person to whom this option is transferred by will or the laws of descent and
distribution. Except as otherwise indicated by the context, the term
"Executive", as used in this Option, shall be deemed to include the estate of
the Executive, or any person who acquires the right to exercise this Option by
bequest or inheritance or otherwise by reason of death of the Executive or the
Executive's legal guardian in the event of disability.

         (f)      TERMINATION FOR CAUSE.

         If the Executive, prior to the Expiration Date, ceases his employment
with the Company or a Subsidiary because he is discharged for "Cause" (as
defined below), the right to exercise this Option shall be terminated
immediately by the Company upon such cessation of employment. "Cause" shall be
defined as and be limited to, conviction of a felony or willful misconduct or
gross negligence in the performance of duties which result in material harm to
PictureTel, as determined by the Compensation Committee of the Company, which
determination shall be conclusive.

         (g)      INVOLUNTARY TERMINATION-WITHOUT CAUSE.

         If prior to the Expiration Date, the employment of the Executive is
terminated by the Company or Subsidiary without Cause, the right to exercise
this Option shall terminate three (3) months after such cessation (but in no
event after the Expiration Date), PROVIDED that this Option shall then be
exercisable only to the extent that the Executive was entitled to exercise this
Option on the date of such cessation.



                                       -2-

<PAGE>   3
         (h)      TERMINATION UPON RETIREMENT.

         If, prior to the Expiration Date, the Executive, prior to the normal
retirement date (as determined by the Committee), retires with the consent of
the Company, as determined by the Committee, the Executive shall be entitled to
exercise this Option on the same basis, terms and conditions as set forth above
in clause (d).

         (i)      LEAVE OF ABSENCE.

         If the Executive, prior to the Expiration Date, is absent from work
under a leave of absence authorized under the Company's then current Human
Resources Policies and he does not return to work within the period provided by
the terms of such leave of absence, he shall be considered as having voluntarily
terminated his employment on such date as provided under the Company's then
current Human Resources Policies. However, for the purpose of calculating the
Percentage of Option Shares Exercisable under Section 2(a) hereof, the period of
the leave of absence shall not be credited and the Executive shall have the
right to exercise only that Percentage of Option Shares Exercisable on the date
the leave of absence commenced, subject to the provisions of Section 2. (i). In
addition, while the Executive is on a leave of absence, he shall not be entitled
to exercise this Option. Upon resuming full status as an employee, the Executive
shall be entitled to exercise this Option, but with the period of leave of
absence not credited under Section 2. (a), and accordingly, the installment
exercise periods in Section 2. (a) shall be appropriately adjusted to give
effect thereto.

    3.       PAYMENT OF PURCHASE PRICE.

         (a)      METHOD OF PAYMENT.

         Payment of the purchase price for shares purchased upon exercise of
this option shall be made by delivery to the Company of cash, certified check,
money order, or bank check (as the Company may require), to the order of the
Company in an amount equal to the purchase price of such shares, or by delivery
to the Company of shares of Common Stock of the Company then owned by the
Executive having a fair market value equal in amount to the purchase price of
such shares, or by delivery of an unconditional and irrevocable undertaking by a
broker to deliver to the Company sufficient funds to pay the exercise price, or
by any combination of such methods of payment. No shares of Common Stock may be
tendered or used in payment of the purchase price payable upon exercise of this
option unless the tendered shares have been held by the Executive for at least
six (6) months.

         (b)      VALUATION OF SHARES TENDERED IN PAYMENT OF PURCHASE PRICE.

         For the purposes hereof, the fair market value of any share of the
Company's Common Stock which may be delivered to the Company in exercise of this
Option shall be equal to the fair market value on the last business day
preceding the date of exercise as determined in good faith by the Committee.

         (c)      DELIVERY OF SHARES TENDERED IN PAYMENT OF PURCHASE PRICE.

         If the Executive exercises this Option by delivery of shares of Common
Stock of the Company, the certificate or certificates representing the shares of
Common Stock of the Company to be delivered shall be duly executed in blank by
the Executive or shall be accompanied by a stock power duly executed in blank
suitable for purposes of transferring such shares to the Company. Fractional
shares of Common Stock of the Company will not be accepted in payment of the
purchase price shares acquired upon exercise of this Option.

    4.       DELIVERY OF SHARES.

         The Company shall, upon payment of the option price for the number of
shares purchased and paid for, make prompt delivery of such shares to the
Executive, provided that if any law or regulation requires the Company to take
any action with respect to such shares before the issuance thereof, then the
date of delivery of such shares shall be extended for the period necessary to
complete such action. No shares shall be issued and delivered upon exercise of
any option unless and until, in the opinion of counsel for the Company, any
applicable registration requirements of the Securities Act of 1933, any
applicable listing requirements of any national securities exchange on which
stock of the same class is then listed, and any other requirements of law or of
any regulatory bodies having jurisdiction over such issuance and delivery, shall
have been fully complied with.




                                       -3-


<PAGE>   4

    5.       NON-TRANSFERABILITY OF OPTION.

         Except as provided in Section 2. (e), this Option is personal and no
rights granted hereunder may be transferred, assigned, pledged or hypothecated
in any way (whether by operation of law or otherwise) nor shall any such rights
be subject to execution, attachment or similar process. Upon any attempt to
transfer, assign, pledge, hypothecate or otherwise dispose of this Option or of
such rights contrary to the provisions hereof, or upon the levy of any
attachment or similar process upon this option or such rights, this Option and
such rights shall, at the election of the Company, become null and void.
Notwithstanding the foregoing, a transfer for estate planning purposes may be
permitted by the Committee in its discretion.

    6.       NO SPECIAL EMPLOYMENT RIGHTS.

              Nothing contained in the Option shall be construed as a contract
of employment between the Company or Subsidiary and the Executive, or as a right
of the Executive to be continued in the employ of the Company or Subsidiary, or
as a limitation of the right of the Company or Subsidiary to deal with the
Executive, and his hiring, discharge, layoff, compensation, and all other
conditions of employment in all respects as though this Option did not exist.
However, during the period of the Executive's employment, the Executive shall
render diligently and faithfully the services which are assigned from time to
time by the Board of Directors of the Company or Subsidiary and shall at no time
take any action which directly or indirectly would be inconsistent with the best
interests of the foregoing entities.

    7.       RIGHTS AS A SHAREHOLDER.

              The Executive shall have no rights as a shareholder with respect
to any shares that may be purchased by exercise of this option unless and until
a certificate representing such shares is duly issued and delivered to the
Executive. Except as otherwise expressly provided in the Option, no adjustment
shall be made for dividends or other rights for which the record date is prior
to the date such stock certificate is issued.

    8.       ADJUSTMENTS IN THE EVENT OF CERTAIN TRANSACTIONS.

         (a)      In the event of a stock dividend, stock split or combination
of shares, recapitalization or other change in the Company's capitalization, or
other distribution to common shareholders other than normal cash dividends, the
Committee will make any appropriate adjustments to (i) the maximum number of
shares that may be delivered under this Option, (ii) the exercise price relating
to this Option, and (iii) any other provision of this Option affected by such
change.

         (b)      In any event referred to in clause (a), The Committee may also
make such adjustments to take into account material changes in law or in
accounting practices or principles, mergers, consolidations, acquisitions,
dispositions or similar corporate transactions, or any other event, if it is
determined by the Committee that adjustments are appropriate to avoid distortion
in the operation of this Option.

    9.       CHANGE IN CONTROL.

         (a)      CHANGE IN CONTROL.

         As used herein, a Change in Control and related definitions shall have
the meanings as set forth in Section 9. (b) below. Immediately prior to the
occurrence of a Change in Control, the Option, to the extent not then
exercisable, shall automatically become fully exercisable.

         (b)      CHANGE IN CONTROL AND RELATED DEFINITIONS.

         A "Change in Control" shall be deemed to have occurred if the
conditions set forth in any one of the following paragraphs shall have been
satisfied: (i) any person is or becomes the Beneficial Owner, directly or
indirectly, of securities of the company representing twenty-five (25) percent
or more of the combined voting power of the Company's then outstanding
securities; or (ii) during any period of not more than two consecutive years
(not including any period prior to December 31, 1995), individuals who at the
beginning of such period constitute the Board and any new director (other than a
director designated by a Person who has entered into an agreement with the
Company to effect a transaction described in Clause (i), (ii), or (iii) of
Section 9.(b)) whose election by the Board or nomination for election by the
shareholders of the Company was approved by a vote of at least two-thirds (2/3)
of the directors then



                                       -4-


<PAGE>   5


still in office who either were directors at the beginning of the period or
whose election or nomination for election was previously so approved, cease for
any reason to constitute a majority thereof; or (iii) the shareholders of the
Company approve a merger or consolidation of the Company with any other
corporation, other than (1) a merger or consolidation which would result in the
voting securities of the Company outstanding immediately prior thereto
continuing to represent (either by remaining outstanding or being converted into
voting securities of the surviving entity) sixty (60) percent or more of the
combined voting power of the voting securities of the Company or such surviving
entity outstanding immediately after such merger or consolidation, or (2) a
merger or consolidation effected to implement a recapitalization of the Company
(or similar transaction) in which no person acquires twenty-five (25) percent or
more of the combined voting power of the Company's then outstanding securities;
or (iv) the shareholders of the Company approve a plan of complete liquidation
of the Company or an agreement for the sale or disposition by the Company of all
or substantially all the Company's assets.

         A "Person" shall have the meaning given in Section 3 (a) (9) of the
Securities Exchange Act of 1934, as modified and used in Sections 13 9D and 14
(d) thereof: however, a Person shall not include (1) the Company, or (2) a
trustee or other fiduciary holding securities under an employee benefit plan of
the Company, or (3) a corporation or other entity owned, directly or indirectly,
by the shareholders of the Company in substantially the same proportions as
their ownership of stock of the Company.

         A "Beneficial Owner" shall have the meaning defined in Rule 13d-3 under
the Securities Exchange Act of 1934, as amended from time to time.

    10.      CERTAIN CORPORATE TRANSACTIONS.

         (a)      In the event of a consolidation or merger in which the Company
is not the surviving corporation or which results in the acquisition of
substantially all the Company's outstanding Stock by a single person or entity
or by a group of persons and / or entities acting in concert, or in the event of
the complete liquidation of the Company or the sale or transfer of substantially
all of the Company's assets (a "Covered Transaction"), all outstanding Options
will terminate as of the effective date of the Covered Transaction, provided
that at least twenty (20) days prior to the effective date of any such merger,
consolidation, liquidation or sale of assets, but subject to clause (b) below,
the Committee shall make all outstanding Options exercisable immediately prior
to consummation of such Covered Transaction (to the extent that such Options are
not exercisable immediately prior to the consummation of the Covered Transaction
pursuant to Section 9).

         (b)      With respect to an outstanding Option held by the Executive
who, following the Covered Transaction, will be employed by a corporation which
is a surviving or acquiring corporation in such transaction or an affiliate of
such a corporation, the Committee may, in lieu of the action of the Committee
described in clause (a) above or in addition to the Option being exercisable
immediately prior to consummation of the Covered Transaction pursuant to Section
9. above, arrange to have such surviving or acquiring corporation or affiliate
assume the Option or grant to the Executive a replacement option which, in the
judgment of the Committee, is substantially equivalent to the Option.

    11.      WITHHOLDING TAXES

         The Company's obligation to deliver shares upon the exercise of this
option shall be subject to the Executive 's satisfaction of all applicable
federal, state and local income tax withholding requirements.

    12.      ADMINISTRATION.

         The Option shall be administered by the Compensation Committee of the
Board of Directors of the Company (the "Committee"), all of the members of which
Committee must be disinterested persons within the meaning of Rule 16b-3 under
the Securities Exchange Act of 1934. Alternately, the Board of Directors of the
Company (the "Board") may serve as the Committee so long as a majority of the
members of the Board are disinterested persons within the meaning of Rule 16b-3.

         The Committee shall have the authority, not inconsistent with the
express provisions of the Option, to adopt, amend, rescind rules and regulations
for the administration of the option, accelerate the time at which all or part
of the Option may be exercised, waive any term or condition of the Option, with
the consent of the Executive, cancel the Option in whole or in part and grant a
new option, and interpret the Option and decide any questions and settle all
controversies



                                       -5-


<PAGE>   6


and disputes that may arise in connection with the Option. Such determinations
and actions of the Committee, and all other determinations and actions of the
Committee made or taken under authority granted by any provision of the Option,
will be conclusive and will bind all parties. A majority of the members of the
Committee will constitute a quorum, and all determinations of the Committee must
be made by a majority of its members.

    13.      EMPLOYMENT RIGHTS.

         This Option does not confer upon the Executive any right to continued
employment with the Company or any subsidiary or affect in any way the right of
the Company or subsidiary to terminate an employment relationship at any time.
Except as specifically provided by the Committee, the loss of existing or
potential profit in this Option will not constitute an element of damages in the
event of termination of an employment relationship even if the termination is in
violation of an obligation of the Company to the Executive.

    14.      MISCELLANEOUS.

         (a)      The grant of this Option will not affect the Company's right
to grant to the Executive options or other awards that are subject to the
Company's Equity Incentive Plan or other plans or are not subject to the plans,
or to issue to the Executive stock as a bonus or otherwise or adopt other plans
or arrangements under which stock may be issued to the Executive.

         (b)      The Committee may at any time or times amend this Option for
any purpose which may at the time be permitted by law, provided that (except to
the extent expressly required or permitted by this Option) no such amendment may
adversely affect the rights of the Executive without the Executive's written
consent.

         (c)      All notices under this Option shall be mailed or delivered by
hand to the parties at their respective addresses set forth beneath their names
below or at such other address as may be designated in writing by either of the
parties to one another.

         (d)      This Option shall be governed by and construed in accordance
with the laws of the Commonwealth of Massachusetts.

         (e)      The Executive may only accept this Option by executing this
Agreement and delivering the Agreement to the Company not later than 5:00 P.M.
Boston time, on FEBRUARY 28, 1999, (the "Offer Termination Date"). Any Agreement
received after the Offer Termination Date shall be null and void and the grant
of this stock option shall be deemed rescinded.


Date of Grant: JANUARY 4, 1999                 PictureTel Corporation
                                               100 Minuteman Road
                                               Andover, MA 01810

                                               By: ____________________________


                             EXECUTIVE'S ACCEPTANCE

         The undersigned hereby accepts the foregoing option and agrees to the
terms and conditions thereof.

                                               EXECUTIVE

                                               Signature: ______________________

                                               Print Name: _____________________

                                               Address: ________________________

                                                        ________________________



                                       -6-