American Board of Opticianry (ABO) Practice Test 2025 - Free ABO Practice Questions and Study Guide

The industry standard for alignment markings on a progressive lens is located on the temporal side of the lens. This positioning is crucial for ensuring that the lens is properly aligned with the wearer's line of sight. When the alignment markings are on the temporal side, it helps in maintaining the correct orientation of the progressive design, allowing the wearer to benefit from the full range of vision provided by the lens—distance, intermediate, and near.

Positioning the markings on the temporal side also plays a significant role in the fitting process. It allows opticians to conveniently adjust the lenses based on the visual needs and anatomical characteristics of the wearer, ensuring that the progressive zones of the lens are properly aligned with the pupil centers. This proper alignment is essential for optimizing the visual experience and minimizing any distortions or discomfort that could arise from misalignments.

The other options do not pertain to the standard placement of alignment markings on progressive lenses. The presence of an etched add power on the lens refers to a feature not typically associated with alignment and is often placed on the front surface. The unit of measurement for ophthalmic prism is relevant for assessing prism effects but does not relate to the specific alignment marks on progressive lenses. Finally, the process of a patient's eyes moving inward to focus