Progressive lenses are a type of multifocal lenses that provide a smooth transition from distance to near vision without visible segments or lines. They are designed to correct presbyopia, a condition that affects most people over 40 and causes difficulty focusing on close objects. Progressive lenses have become increasingly popular due to their aesthetic appeal and functional benefits. However, not all progressive lenses are created equal. There are different types of progressive lens designs, each with its advantages and disadvantages. This book provides a brief overview of the main categories of progressive lens designs, such as conventional, free-form, personalised, digital, and AI-designed progressive lenses. It also explains the key factors that influence the performance and comfort of progressive lenses, such as the fitting parameters, the lens material, the coating, and the frame shape. The book aims to help optometrists, opticians, and eyewear consumers understand the basic principles and features of progressive lens designs and make informed choices when selecting or prescribing them.