What type of pupillary distance (PD) measurement is taken at 30 inches?

The correct type of pupillary distance (PD) measurement taken at 30 inches is Intermediate PD. This measurement is specifically associated with the viewing distance that is not categorized as close (like reading) or far (like distance vision).

Intermediate PD is utilized for tasks that occur at typical computer screen distances, which generally fall around 30 inches. This is important for ensuring that lenses are properly aligned with the patient’s line of sight at that specific distance, allowing for optimal vision correction, particularly for computer use or other intermediate visual tasks.

In contrast, Near PD would be measured for tasks closer than 30 inches, such as reading. Distance PD is measured for more extensive viewing distances, typically more than 40 inches away. Variable PD tends to imply measurements that adjust for different distances or activities but does not specifically designate a standard distance like 30 inches. Thus, recognizing the context of how intermediate PD fits within typical use cases solidifies why it is the correct response in this scenario.