7.7 Case Study 2: Optical coatings

Should you need spectacles, you will doubtless be aware that opticians can now offer a bewildering choice of different materials and an array of surface treatments to enhance the spectacle lenses, from antiglare coatings to scratch resistance. How do you decide whether to pay for the extra protective coating that is offered and should you choose glass or plastic lenses? What are the materials properties that are important and why are coatings required? The terminology contained in Optical terms will help you work through this section.