Pupil diameter estimation in visible light

Pupil size is a valuable source of information since it can reveal the emotional state, fatigue and ageing process. A lot of research has been carried out in this area with clinical and even psychiatric validity, since the fluctuations in the size of the pupil are closely linked to the autonomic nervous system. The pupil size analysis of oscillations due to contraction and dilation could be a useful instrument for diagnosis of disorders related to their own control mechanisms and an index of neurological disease affecting other nerve centres. Pupillography is the pupil size clinical examination which involves the use of infrared light, which allows performing an optical analysis of the pupil, varying the light conditions and measuring the pupillary diameter in different luminance levels. The aim of the proposed work is to exploit video processing techniques in visible light to calculate the pupil diameter and analyse the pupil diameter changing as a result of the lighting conditions variation.