What is the main physiological effect of alcohol consumption on a driver's visual perception?

1. It improves peripheral vision and reaction time
2. It narrows peripheral vision (tunnel vision / visión de túnel), degrades depth perception, and impairs night vision recovery after glare
3. It enhances night vision acuity by dilating pupils
4. It has no measurable effect on vision if BAC is under 0.80 g/l