Download your FREE information guide

Take the first step towards better vision.

Subscribe to our updates
Your personal data is secure, see our privacy policy


What is it?

Put simply, pupillometry refers to measuring pupil size. A pupillometer measures your average pupil size, the variation in pupil size over a fixed period, and the difference in pupil size in both eyes at three different light levels.

Pupillometry involves the patient looking at a spotlight through padded eyepieces. The clinician is then able to measure the size of each pupil in three different light settings using an infrared camera.

What are the Benefits?

Accurate pupillometry is an essential part of the screening process for Laser Eye Surgery.

The lasers used in Laser Eye Surgery are only capable of treating a defined area of the eye – typically, a circle with a diameter of between 6-8mm. As such, some patients with larger pupils can only be treated with specific lasers that are capable of covering larger areas.

If a laser with smaller coverage capacity is used, an untreated section would be left around the corrected part of the eye; it would be like looking through a clear patch in the middle of a smeared window.

Furthermore, accurate pupillometry can help to minimise the risk of night vision changes post-surgery. While starbursts and halos are a common temporary side effect of Laser Eye Surgery, some patients are more at risk of more significant night-time vision changes. Accurate pupil size measurements that are taken in the dark and in dim lighting conditions can help your surgeon to optimise your treatment plan to minimise this risk.

What will I feel?

Pupillometry does not require the instrument to make direct contact with your eye. Therefore, you won’t feel anything during this step of the screening/aftercare process.