Plastics offer a lightweight, cost-effective alternative to traditional optical materials like glass and crystal, making them an increasingly popular choice for a variety of optical applications. Common optical plastics include polymethyl methacrylate (PMMA), polycarbonate, and cyclic olefin copolymer (COC), each with its own set of advantages and limitations. For instance, PMMA is known for its excellent light transmittance and ease of fabrication, while polycarbonate provides higher impact resistance. Plastics are widely used in consumer electronics, automotive lighting, and even in some medical devices, where their lightweight nature and moldability offer distinct advantages. They are particularly well-suited for mass production techniques like injection molding, which allows for the creation of complex optical elements at scale. However, plastics generally have lower refractive indices and can exhibit higher levels of optical dispersion compared to glass, which can be a limitation in high-precision applications. They are also more susceptible to environmental factors such as temperature fluctuations and UV degradation, requiring special additives or coatings for long-term stability. Advances in polymer science are leading to new types of optical plastics with improved characteristics, including higher refractive indices and lower levels of dispersion, expanding their range of potential applications. Overall, plastics provide a versatile and economically viable option for many optical systems, and ongoing research promises to further extend their capabilities.