Certified Ophthalmic Technician Practice Test 2025 – Complete Exam Prep

The round seg bifocal lens is commonly associated with causing image jump due to the abrupt change in lens power between the distance and near vision zones. When a wearer looks down through the segment for near vision, there is a noticeable jump in the perceived image, as the segment is a distinct section of the lens with a different curvature and power. This jump can be particularly pronounced because the round segment does not seamlessly blend into the distance portion of the lens.

In contrast, flat-top bifocal lenses, while they also have distinct sections for distance and near vision, generally provide a less pronounced jump due to their design, which offers a more gradual transition. Single vision lenses do not have different zones, so there is no image jump at all. Progressive lenses are designed to provide a smooth transition between different viewing distances without a significant jump, as they have a gradient of increasing power rather than a sudden change. Thus, the round seg bifocal lens stands out as the type that typically results in an image jump.