What does it mean if a frame is classified as "adjustable"?

A frame classified as "adjustable" primarily indicates that it can be tailored in fit and comfort for individual wearers. This classification allows for modifications to be made to better suit the physical characteristics and preferences of the wearer, enhancing both comfort and functionality. Adjustable frames are especially beneficial because they accommodate variations in head size, shape, and personal fit preferences, ensuring that the glasses or goggles align well with the user's facial structure.

While other options may touch on aspects related to adjustments, they do not encapsulate the core meaning of "adjustable" in the context of eyewear or frames. For instance, simply being designed for multiple size adjustments over time might suggest durability but doesn't emphasize the immediate customizability for individual wearers that an adjustable frame provides. Additionally, the notion that adjustable frames are only for sports and outdoor activities is a limitation that does not reflect the broader applicability of these frames across various uses. Lastly, while flexibility in materials can contribute to a frame's adjustability, it doesn't wholly define what it means for a frame to be adjustable in terms of fitting the unique requirements of an individual.