Final answer:
As a person's BAC goes up, their field of vision is reduced due to the effects of alcohol on the central nervous system.
Step-by-step explanation:
As a person's BAC (blood alcohol concentration) goes up, their field of vision is reduced. This is because alcohol affects the central nervous system, including the brain and eyes. Alcohol consumption leads to a decrease in visual acuity and can impair depth perception, peripheral vision, and overall reaction time.