“The photic sneeze reflex is a reflex condition that causes sneezing in response to numerous stimuli, such as looking at bright lights or periocular (surrounding the eyeball) injection. The condition affects 18–35% of the world's population”
Also known as 'Autosomal Compelling Helio-Ophthalmic Outburst' (ACHOO) syndrome.1)
It's cause, and the tendency for inheritance within families, are unknown.
Also see :