Which in-office modification is considered the easiest to perform on a lens?

Truncation is regarded as the easiest in-office modification to perform on a lens. This process involves removing a small portion from the edge or bottom of the lens to enhance fit or aesthetics, primarily for certain types of contact lenses, like peripheral zones in specialty lenses. The procedure is relatively straightforward, often requiring only basic tools and minimal skill, making it accessible for most eyecare professionals.

In contrast, edge polishing, centering, and changing the prescription typically require more intricate processes and skills. Edge polishing involves smoothing and refining the lens edges, which may demand specific machinery and techniques. Centering can require precise measurements and adjustments to align the lens correctly with the pupil for optimal vision. Changing the prescription typically necessitates entire new lenses or significant modifications that extend beyond simple in-office tasks. Thus, truncation stands out for its simplicity and ease of execution in an office setting.