This is interesting, I have found through my own experience, (having Aspergers), and through observation of children with Aspergers (a form of austism), that most are photophobic. They do not tolerate bright lights, and can become very stressed in brightly lit surroundings, bright lights can exacerbate symptoms. This seems to apply to artificial lighting, more than natural sunshine. A slow pupil response would account for this aversion to bright light, and the resultant stress behaviour.