# Vertex distance: record the wearing position

Back vertex distance is the separation between the back surface of the lens and the front of the cornea.

## When to check

Record it with the frame adjusted in its actual wearing position. If the adjustment changes, recheck before using the value in a personalized order.

## Laboratory communication

Specify the unit and measurement procedure. Follow the selected design guide to determine which parameters are used.

## Limit

This page does not compensate prescriptions. Do not apply an automatic correction simply because a vertex distance measurement is available.

## References

- [ZEISS — Individualized eyeglass lenses](https://www.zeiss.com/vision-care/us/eye-health-and-care/understanding-vision/whats-the-difference-between-individualized-eyeglass-lenses-and-off-the-shelf-lenses.html)

## Related topics

- [Optical centration: from measurement to fitting](https://lensas.com.br/en/knowledge/optical-centration/)
- [Pantoscopic tilt: measurement and convention](https://lensas.com.br/en/knowledge/pantoscopic-tilt/)

Educational content · Fictional examples · Automated technical review, no claimed clinical validation.

Canonical: https://lensas.com.br/en/knowledge/vertex-distance/
Version: 2026-09-15.1