Preserve the format you were given
A measurement may arrive as one total or as separate right and left values. Keep the source document with those labels. The wearer’s right side is not necessarily the right side of a photograph viewed by somebody else, so do not relabel a pair of numbers by looking at a selfie.
Add without replacing the original
Our helper can add a recorded right value and a recorded left value to show a total. That is useful arithmetic, but the original pair may still be the information needed for an order. Keep both the total and the separate labels in your notes rather than replacing the original record.
Avoid the tempting shortcut
Do not split one total into equal halves and call the result measured monocular PD. A convenient calculator cannot supply information that was never measured. If a form requests a different format from the one you have, contact the dispensing professional or the store.
Check the intended use
Make sure the measurement supplied belongs to the task the glasses are intended for. A distance order and a reading-only order should not be treated as automatically sharing the same fitting information. Request clarification rather than applying an internet conversion formula.
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