A book explaining vision disorders, ophthalmic prescriptions, the different types of lenses and the materials used to make them, the different treatments, the various shades, how lens size affects lens thickness, situations faced when consulting for new glasses. Three demonstrations are available to be used. Also covered are the different facets used to sell you glasses, which do not specifically meet your expectations, but which make sure to meet the distributor's. Knowing what subtleties are put in place, you'll be better able to cope with them, to ensure that your ophthalmic eyeglasses meet your financial and visual needs.