Disclosed are methods for preparing a laminate incorporable to a surface of an optical lens. A front surface and/or back surface of a photochromic film or a functional film is pre-treated. A second thermoplastic film is then laminated on each pre-treated surface of the photochromic film or functional film using a water-based adhesive. The pre-treatment applied on the surface(s) of the photochromic film or functional film enables the formation of strong adhesion between the second thermoplastic film and the water-based adhesive.