What component of a bifocal lens helps with distance vision?

The distance portion of a bifocal lens is designed specifically to aid in seeing objects that are far away, allowing the wearer to focus on distant vision clearly. Bifocal lenses typically consist of two distinct zones: one that addresses distance vision and another that caters to near vision. The distance portion is usually the upper part of the lens, which retains a standard curvature to assist with viewing objects at a distance, such as when driving or watching television.

In contrast, the near portion is focused on facilitating close-up tasks like reading and is located in the lower part of the lens. The transition zone, while helpful in some multifocal designs, is not a defined segment with its own refractive power but rather where the lens gradually changes from the distance to the near portion. The reading segment, similar to the near portion, is dedicated to magnifying close tasks.

Thus, the distance portion plays a critical role in bifocal lenses, emphasizing its importance in the design and functionality of lenses for individuals needing both near and distance vision correction.