Progressive power lenses

With the rapidly increasing public awareness of progressive power lenses for the correction of presbyopia, there has been a corresponding proliferation of manufacturers and types of progressive lens designs. This paper discusses the various lens design philosophies, often grouped in "hard" and "soft" categories. In the absence of visible multifocal segment lines, problems arise in attempting to identify the various lens types, in neutralizing progressive lens powers and in dispensing. These problems are discussed from the viewpoint of the refractionist. The advantages and disadvantages of progressives are considered, together with their indications and contraindications.