What is the maximum angle used for a bifocal segment called?

The maximum angle used for a bifocal segment refers to the specific parameter that determines how far down the segment is positioned on the lens. This is commonly known as the segment height. The segment height is crucial for ensuring that the bifocal lens accommodates the user’s visual needs effectively, allowing for a clear line of sight through the reading segment when the wearer looks down.

When fitting bifocal lenses, it’s important to measure this segment height accurately because it affects comfort and the ease of transitioning between the distance and near vision zones. A well-measured segment height helps in placing the bifocal segment at the appropriate distance from the pupil, thus optimizing visual performance for tasks that require near vision.

Understanding the purpose and application of segment height is essential in ophthalmic dispensing practice, as it directly impacts the effectiveness of the prescribed lens for the patient’s needs.