What characteristic do progressive lenses possess?

Progressive lenses are designed with a gradual change in lens power from the top of the lens to the bottom. This characteristic allows for a seamless transition between different vision zones, enabling the wearer to see clearly at various distances—far, intermediate, and near—without the visible lines found in bifocal or trifocal lenses. The top portion of the lens is generally optimized for distance vision, while the bottom part accommodates reading or close-up tasks.

This design is particularly advantageous for individuals with presbyopia, as it provides a more natural visual experience. It allows the wearer to look through different parts of the lens to focus on objects at varying distances, rather than having fixed zones or focal points.