Why do you sometimes need a height measurement?Updated 3 hours ago

For most prescriptions, your PD is all we need. For stronger ones, we also need a height measurement: how far up the lens your pupil sits when you are wearing that particular frame.

The stronger a lens is, the more the vision changes across it. Getting the height right means you look through the correct part of the lens rather than slightly above or below it.

When we will ask for it

We need a height measurement if any of these apply to your prescription:

• The sphere (SPH) is outside −6.00 to +6.00
• The cylinder (CYL) is outside −3.00 to +3.00
• It contains prism, at any strength

Sphere and cylinder are looked at separately, so only one of them needs to be outside the range. If your prescription sits inside these ranges, we will not need to ask.

How to get one

Heights are measured while you wear the frame, so they cannot be taken from a photograph or a previous prescription.

• Visit any Cubitts store. We will measure it free, in a couple of minutes. No appointment is needed.
• If you have ordered the same frame from us before, we may already have your heights on file and can reuse them. Heights are specific to the frame, so a different style will need a new measurement.

What happens to my order

We will hold your order and contact you rather than guess. If getting to a store is difficult, tell us and we will find another way forward.

A strong prescription is not a problem

Needing heights does not mean we cannot make your spectacles. It means we want to make them accurately.