In a progressive addition lens, what is the "progressive zone" commonly known as?

The "progressive zone" in a progressive addition lens is commonly referred to as the corridor. This area is crucial as it is the smooth transition zone that allows the wearer to shift focus from distance to intermediate and near vision without the abrupt changes associated with traditional bifocals or trifocals.

The corridor typically has a gradual increase in power, which helps to facilitate a more natural visual experience when looking at objects at different distances. Proper design of this corridor is vital for ensuring that users can seamlessly adapt to their lenses, minimizing disruptions to their visual comfort and performance.

Other terms might describe different parts of the lens or specific functions within the lens design, but the corridor specifically refers to that progressive zone which plays a central role in the function of progressive lenses.