Oh, if it can be fixed, it must be a really great work. I never hear that. If you broken your plastic eyeglasses lenses, why not buy a pair new of eyeglasses instead? Now, with the development of E-Commerce, cheap yet quality prescription glasses are available online. Sometimes, you can also get free eyeglasses from online. Be good to your eyes and buy a pair of new and suitable eyeglasses.
Sorry to hear that. Actually, the plastic eyeglasses lenses can not be fixed. Even though you can use glue to stick them together, it can affect your vision. So here I kindly suggest to you buy a pair of new glasses which will not damage your eyes.