pupillietäisyys
Pupillietäisyys, often abbreviated as PD, refers to the distance between the centers of the pupils of an individual's eyes. This measurement is crucial in optometry and ophthalmology, particularly when fitting eyeglasses and contact lenses. The PD is typically measured in millimeters and can vary significantly between individuals. Factors such as age, ethnicity, and sex can influence the average PD. For instance, children generally have a smaller PD than adults, and certain ethnic groups tend to have different average measurements.
Accurate PD measurement is essential for several reasons. When glasses are made, the optical centers of the
There are several methods for determining PD. Optometrists and ophthalmologists commonly use a ruler or a specialized