On the ocular anatomy, the black circular orifice located at the center of the iris is defined as the pupil through which light enters the eye.

The characteristic of the pupils, which normally have equal amplitude on the pair of eyes, is that of dilating or narrowing according to light conditions. When there is little amount of light, the eye has difficulty capturing it, so the pupil, thanks to the muscular apparatus of the iris, widens to try to capture light as much as possible. When, on the other hand, there is too much amount of light, to avoid glare, the pupils shrink.

If a patient has to undergo a refractive surgery for the treatment of nearsightedness, farsightedness, astigmatism or cataract, it is essential that he performs a pupillometry before the surgery.

This examination, aimed at measuring the diameter of the pupil and its response to light stimuli, is in fact, necessary for the surgeon to evaluate the suitability of the patient’s pupil for treatment and to avoid any post-operative nuisances such as night halos and glare phenomena.

Pupillometry is performed with a specific device called a pupillometer, often associated with corneal topographers. The patient is asked to sit in front of the instrument that detects the pupil’s measurements in different light conditions.

Completely painless, rapid (about 20 seconds per eye) and absolutely non-invasive, pupillometry does not require any preparation or use of eye drops.