. options outstanding under the 2000 plan generally vest 4 years from the date of grant and options awarded expire ten years from the date of grant . the company has a nonqualified stock option plan for non-employee directors ( the 201cdirectors 2019 plan 201d ) . the directors 2019 plan , as amended , was adopted in july 1989 and provides for grants of options to purchase shares of the company 2019s common stock to non-employee directors of the company