While driving at night along a rural two-lane road, a driver who has consumed alcohol is temporarily blinded by the bright headlights of an oncoming vehicle. After the oncoming car passes, the driver experiences a prolonged period of temporary blindness and takes significantly longer than normal to regain clear vision of the dark roadway. Which physiological effect of alcohol directly causes this delayed vision recovery?
- Slowed autonomic pupil response, which impairs the eyes' ability to adjust to rapid changes in light and delays glare recovery time.Answer
- BEnhanced peripheral vision sensitivity, which causes side light sources to override central focus during night driving.
- CComplete immunity to headlight glare, provided the driver's Blood Alcohol Concentration remains below the 0.08% adult legal limit.
- DTemporary paralysis of the optical nerve that prevents the activation of high-beam headlights when meeting traffic.
Answer
Alcohol depresses central nervous system functions, slowing the automatic constriction and dilation of pupils. This delays the eye's dark adaptation and lengthens glare recovery time after exposure to oncoming headlights at night.
The correct answer correctly identifies that alcohol acts as a central nervous system depressant, slowing autonomic muscular control of the pupil. When exposed to bright headlights at night, an impaired driver's pupils contract slowly and dilate slowly once the light source passes, leading to extended glare recovery time and temporary blindness.
Step-by-Step Solution
Key Concept
Glare recovery and dark adaptation impairment due to alcohol depressant effects on pupil reflex timing.
Estimated Time:1m 0s