The present invention relates to a method for manufacturing a prescription lens. In one implementation, the tilt sensor shuts off a UV light included in the cleaning device’s operations. A data vector may be embedded into a set of corresponding ordered embedding sites by representing each data element as different intensity values assigned to the pixels within one portion of an embedding site relative to the pixels in another portion of the embedding site. The resulting precompensation filter is determined as the product of at least two scalar dynamic systems, represented by an inverse of a characteristic scalar magnitude response in the frequency domain representing the power gains at the listening positions, and the causal FIR filter designed to approximately invert only non-minimum phase zeros that are safely inverted. The electrode structure defines a ladder filter in which at least two ground pads of a plurality of ground pads, to be connected to a ground potential, provided on the piezoelectric substrate are electrically connected by a connection conductor provided on the dielectric layer, and all of the ground pads are electrically connected. In so doing, a portable media player can then utilize this information to provide for the maximum functionality of the accessory when connected to the portable media player.