What is the simplest means of identifying an unknown PALs lens?

Surface engraving is the simplest means of identifying an unknown progressive addition lenses (PALs) lens because most manufacturers embed specific identifying engravings or markings on the lens surface. These engravings often contain vital information such as the brand, prescription, or additional specifications relevant to the lens design.

These engravings allow for quick reference, making it straightforward for optical professionals to determine the lens type without needing to conduct more complex tests or measurements. By simply examining the surface of the lens, one can quickly ascertain essential details that would otherwise require more time-consuming processes.

While techniques like light transmission testing, lens thickness measurement, and coating analysis can provide valuable information about a lens' properties, they may not necessarily lead directly to identifying the specific type or brand of the lens. Therefore, surface engraving stands out as the most efficient and effective method for lens identification.