Pupillary Distance (PD) Measurement

For those who have a prescription of more than + or - 2.50, we will need the distance in millimetres between the centre of your two eyes. It is easy to obtain this, just asks a friend to hold a millimetre rule just above the centre of your eyes and measure the distance between the outside edge of one pupil to the inside edge of the other pupil.

Both of you should be at the same height approximately, sat opposite each other. The measurer holds the ruler in their left hand across the bridge of your nose and closes their LEFT eye to avoid any parallax error. With their RIGHT eye open, they then first line up the ruler with outside edge of your left pupil. Then without moving the ruler they close their RIGHT eye and with their LEFT eye read off the measurement to the inside edge of RIGHT pupil. (See diagram)

You should fix on an object. E.g. the open eye of the measurer. This should ideally be about 40 centimetres, 16 inch (400mm) away.

This measurement will ensure the accuracy of your spectacle lenses when supplied.

A typical measurement will usually be somewhere between 55mm and 72mm