Final answer:
The digital Essilor pupillometer can be set to measure 'distance' or 'near' PDs, providing essential data for creating accurate prescription lenses.
Step-by-step explanation:
The digital version of Essilor's pupillometer is designed to measure pupillary distances (PD) necessary for fitting corrective lenses accurately. It has the capability to be set to measure either distance or near PDs. The correct answer to the student's question is:
A) Distance near
This refers to the pupillary distance for looking at objects far away (distance PD) and for looking at objects up close (near PD). These measurements are crucial for creating prescription glasses that will help individuals focus at various distances.