In a flash photo, one eye has a red reflection, while the other flashes back white

This question is very important because an observation of a white pupil should always be taken seriously. The origin of this white pupil can be malformative, it can be infectious, it can be accidental, but it can also have a cancerous origin.

It is also the only cancer in children that is recognisable, precisely by a white pupil, and it calls for an urgent consultation with a specialist.