Eye-Opening study: pupil size may reveal pain levels

NCT ID NCT02628314

First seen Jun 27, 2026 · Last updated Jul 31, 2026 · Updated 1 time

Summary

This study tested whether changes in pupil size can reliably measure pain. Twenty adults with hip or knee arthritis received brief heat pulses while researchers recorded their pupil responses and pain ratings. The goal was to see if pupil diameter could serve as an objective pain indicator.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

What this could lead to
If successful, this could lead to a simple, objective way to measure pain using pupil response.
What could go wrong
This is a small, early-stage study with only 20 participants. It only tests reliability, not a treatment, so results may not lead to a practical tool.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for OSTEOARTHRITIS are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Wake Forest Baptist Medical Center

    Winston-Salem, North Carolina, 27157, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.