A new pair of glasses on a leather tray on a dark counter, an open glasses case beside it.

From order to wear

Dispensing

Optical glossaryFrom order to wear

The professional work between prescription and finished glasses: frame selection, measurement, fitting, and adjustment. Where most of a lens's real-world performance is decided.

The optician's part of a pair of glasses, in order. The measurements are only as good as the frame they are taken in.

Illustrative · the shape of the principle, not measured data

In more depth

Dispensing starts with choosing a frame that fits the face and suits the prescription, then adjusting it before anything is measured. The optician takes PD and fitting heights in that adjusted frame, and for individualized designs its tilt, wrap and vertex distance as well.

When the lenses come back, they are checked against the order for power, axis, and centration, fitted, and the frame is adjusted again on the face. A good dispenser also explains what the first days will feel like. Most of the difference between a lens that feels right and one that doesn't is decided here.

Related terms

Fitting heightThe vertical distance from your pupil center to the bottom of the lens in your chosen frame. The most common cause of progressive remakes when wrong.Monocular PDYour PD measured separately for each eye, from the nose bridge. More accurate than a single figure, and required for individualized lenses.RemakeA lens made again due to error or non-adaptation. The most common causes: fitting height and frame changes after measurement.Vertex distanceThe gap between the back of the lens and your eye. At strong powers, a change in this distance changes the effective prescription.

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