- Decreased visual performance: Your overall visual performance may be altered since drinking heavily impairs brain function. You may have blurred vision or double vision due to weakened eye muscle coordination. You may also experience delayed reactions while driving.
- Slow pupil reactions: Alcohol tends to affect the speed at which your iris constricts and dilates. A driver that has been drinking alcohol cannot adapt as quickly to oncoming headlights.
- Decreased peripheral vision: Drinking alcohol has also been shown to decrease the sensitivity of your peripheral vision. This may give you the effect or perception of having tunnel vision.
- Decreased contrast sensitivity: Drinking too much alcohol can alter your contrast sensitivity, or how precise you can discern between shades of gray. Driving in rain or fog will be much more dangerous.
- Optic neuropathy: Also referred to as tobacco-alcohol amblyopia, people who drink or smoke in excess can develop optic neuropathy. You might develop a painless loss of vision, decreased peripheral vision or reduced color vision. Even though studies have shown the vision loss to be a result of a nutritional deficiency, some professionals believe that the condition develops because of toxic effects of alcohol and tobacco.
- Frequent migraines: Alcohol has been shown to be a trigger for severe migraine headaches in some people. You may experience a temporary, but debilitating visual aura before the onset of the headache. The visual aura may appear as blind spots, graying of vision or zig-zag patterns of light.
- Poor cosmetic appearance: Drinking can cause eye redness. Alcohol causes the blood vessels in your eyes to expand, making them more prominent.
Alexander, Larry J, OD. Primary Care of the Posterior Segment, Third Edition. Mcgraw-Hill, 2002.