Optician License Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The term that refers to the displacement of the lens optical center away from the boxing on datum center of the frame's lens aperture is known as decentration. This concept is crucial in optics, particularly in the fitting of lenses into frames. Decentration occurs when the optical center of the lens does not align with the geometrical center of the lens as defined by the boxing measurements. This misalignment can affect visual acuity, especially if not taken into account during lens fitting.

Understanding decentration is important for opticians because it can influence how light passes through the lens and how the lens functions in relation to the wearer's visual needs. Correctly calculating and applying decentration ensures that the lenses are positioned optimally for the best visual performance. In contrast, the other options—offset, misalignment, and deviation—are related concepts but do not specifically address the displacement of the lens optical center from the boxing in this particular way.