Is night blindness caused by pupils not dilating sufficiently?

No, night blindness is not caused by pupils not dilating sufficiently. Night blindness is a condition in which a person has difficulty seeing in low-light conditions. It is caused by a deficiency of rhodopsin, a pigment in the retina that is responsible for vision in dim light. When there is not enough rhodopsin, the retina is not able to detect light as well, and the person experiences night blindness.