7.1 Why Combine Different Optical Elements?7.2 Analysis of Lens Aberrations7.3 Improvement of Optical Functionality7.4 The Generation of Novel Optical Functionality7.5 Waveguide-based Hybrid Optics7.6 Reducing Weight, Size and Cost7.7 Specifying Hybrid Optics in Optical CAD/CAM7.8 A Parametric Design Example of Hybrid Optics via Ray-tracing Techniques