A unified formula for light-adapted pupil size

Abstract

The size of the pupil has a large effect on visual function, and pupil size depends mainly on the adapting luminance, modulated by other factors. Over the last century, a number of formulas have been proposed to describe this dependence. Here we review seven published formulas and develop a new unified formula that incorporates the effects of luminance, size of the adapting field, age of the observer, and whether one or both eyes are adapted. We provide interactive demonstrations and software implementations of the unified formula.

Pupillometry of taste: Methodological guide – from acquisition to data processing - and toolbox for MATLAB

“…The subject would be freer to move. However, this would make it necessary to deal with light variations and to constantly make measurements with a light meter to eliminate pupil variations due to the light (pupil light reflex) (Watson & Yellott, 2012). Another limit is that emotions cannot be qualified with pupillometry alone.…”

A Review of Pupillometry for Human-computer Interaction Studies

“…In the following paragraphs, I will highlight the major influences on pupil reactivity that are relevant when conducting HCI studies. As already mentioned, age is a major factor in many parameters of the PLR and should be accounted for in all studies [14]. Older participants show decreased amplitude of response [21], increased latency and in some cases decreased velocity [20] as well.…”

“…The normal range of pupil diameter is between 2 and 8 mm [14] but resting values are not simply a consequence of lighting condition and eyeball size [15]. There can be considerable difference between users based on their baseline ANS activity balance.…”

Paper No P17: A Spherically Shaped Display for Use as an Artificial Iris

“…Its inner diameter generally varies between 2 mm in very bright lighting conditions and 8 mm in very dim conditions, with 3 mm being the dimension with the best overall performance [5].…”