Progressive lenses, also known as multifocal lenses or PALs (progressive addition lenses), are a lenses designed to provide clear vision at multiple distances without the need for separate pairs of glasses. PALs are primarily used to treat presbyopia, an age-related condition that affects the eye’s ability to focus on up-close objects.
Progressive lenses provide a smooth and seamless transition between different prescription strengths within a single lens. Unlike traditional bifocal or trifocal lenses, progressive lenses do not have visible lines separating the different prescription strength zones. Instead, the lenses gradually change in power from the top (distance vision) to the bottom (near vision), with intermediate powers located in between.
The lens is divided into three parts:
- Distance vision: the upper portion
- Intermediate vision: the middle portion
- Near vision: the lower portion
