A vehicular cabin monitoring system includes first and second cameras disposed respectively at first and second positions within an interior cabin of a vehicle and respectively viewing first and second regions. A light emitter is operable to emit near infrared light that illuminates the first region. Based on image data captured by the second camera, the system detects an occupant within the interior cabin and determines a distance between the occupant and the light emitter. Based on image data captured by the first camera, the system determines luminance of near infrared light within the first region. Responsive to determining that the luminance is greater than a threshold luminance, the system reduces intensity of the near infrared light. Based on the distance between the occupant and the light emitter being greater than a threshold distance, the threshold luminance is greater than when the distance is less than the threshold distance.