PD stands for

PD stands for

• A. Pupil diameter
• B. Pupillary distance
• C. Posterior diameter
• D. Pressure drop

Answer: (B)

PD is Pupillary Distance—the distance between the centers of your pupils. This measurement is essential when fitting glasses because it aligns the lenses’ optical centers with your pupils, helping you see clearly and comfortably without eyestrain. PD can be taken for distance or near vision, and it can be a single binocular number or separate numbers for each eye when needed for certain frames. This is different from pupil diameter, which is the size of the opening in the iris that changes with light and has no role in lens alignment. The other terms aren’t used in eye care for this measurement, so PD specifically refers to the distance between your pupils.

PD is Pupillary Distance—the distance between the centers of your pupils. This measurement is essential when fitting glasses because it aligns the lenses’ optical centers with your pupils, helping you see clearly and comfortably without eyestrain. PD can be taken for distance or near vision, and it can be a single binocular number or separate numbers for each eye when needed for certain frames. This is different from pupil diameter, which is the size of the opening in the iris that changes with light and has no role in lens alignment. The other terms aren’t used in eye care for this measurement, so PD specifically refers to the distance between your pupils.