Single vision and progressive lenses are distinct types of eyeglass lenses, and the key difference between them lies in how they correct vision:
Single Vision Lenses:
* Single vision lenses have a uniform prescription power across the entire lens.
* They are used to correct a specific vision problem, such as myopia (nearsightedness), hyperopia (farsightedness), or astigmatism.
* These lenses are ideal when you need vision correction for a single focal distance, whether it's for clear distance vision or close-up (reading) vision.
* They are not designed for multifocal vision needs, meaning they are not suitable for individuals with presbyopia who require clear vision at varying distances.
Progressive Lenses:
* Progressive lenses are multifocal lenses that offer a gradual transition of prescription power from the top of the lens (for distance vision) to the bottom (for reading or close-up vision).
* They are primarily used to address presbyopia, an age-related condition that makes it difficult to focus on close-up objects, in addition to addressing distance vision needs.
* Progressive lenses provide clear vision at different focal distances, including intermediate vision for activities like computer use.
* They eliminate the need for multiple pairs of glasses and offer a seamless, cosmetically appealing solution for vision correction at various distances.
In summary, the primary difference is that single vision lenses correct vision for only one specific distance (either near or far), while progressive lenses are multifocal and are designed to provide clear vision at multiple distances. Progressive lenses are typically used by individuals with presbyopia who require correction for both close-up and distance vision, as well as everything in between.