Although alcohol is an intoxicating substance, it is legal to consume in the United States for people ages 21 and older. The Centers for Disease Control and Prevention (CDC) note that there is no truly safe level of alcohol consumption, but drinking no more than moderate amounts of alcohol lessens the impact of drinking on the body and mind.
The CDC reports that 88,000 people die every year due to excessive alcohol consumption. Between 2006 and 2010, people who drank too much alcohol took an average of at least 30 years off their lives, whether due to an accident or a terminal illness. Alcohol is responsible for one out of every 10 deaths among working-age adults, 20-64 years old.
Many of the problematic side effects of excessive alcohol consumption are well known. Damage to the brain, heart, and liver are all well documented, in both acute and chronic illnesses. Abuse, dependence, and addiction to alcohol are all serious long-term risks of drinking too much. Struggling with these conditions increases the risk of accidents, poisoning, chronic illness, mental health struggles, job loss, and problems in relationships.
One of the short-term effects of excessive alcohol consumption is changes to eye sight. Blurred vision and double vision can be temporary effects of intoxication, and they typically wear off as the person sobers up or the next day. However, alcohol can also contribute to long-term changes to vision.
Blurry Vision from Drinking Alcohol
The liver metabolizes about one serving of alcohol per hour. Starting about 15 minutes after a person begins drinking, the liver will take over and break alcohol down into different molecules, which interact with the body and brain in certain ways. If the person steadily drinks about one beverage per hour, then they will not raise their blood alcohol content (BAC) very much; however, if they consume two or more beverages in an hour, they are likely to raise their BAC to the legal limit of 0.08% or higher.
- .02%-0.03%: Effects include slight lightheadedness, relaxation, and a little euphoria; however, there is no loss of physical coordination, and other depressant effects are not apparent yet. This is the equivalent of the first drink of the hour.
- .05%-0.06%: The person may experience a feeling of physical warmth, perhaps the beginning of facial flushing, and shyness dissipates. The person becomes more gregarious and has lowered inhibitions in other ways, including talking louder, exaggerated behavior, and intensified emotions. Mood swings begin.
- .08%-0.09%: This is about two drinks in one hour, and it is the legal limit at which a person can no longer drive since motor function, reaction times, and physical coordination are all affected. However, at this stage, many people believe they function better than they actually do. Sight and hearing are diminished because the brain does not process input as rapidly.
- .1%-0.12%: Loss of judgment and physical coordination occurs. The person “acts drunk,” including stumbling, slurred speech, emotional changes, and more. Some people become belligerent, loud, or aggressive while others may be euphoric, sleepy, or sad.
- .14%-0.17%: Loss of physical control and gross motor impairment occur. There is a major loss of balance as well as definite vision changes, especially blurred or double vision. Euphoria likely gives way to unpleasant emotions. There is an increased risk of an accident from falling or experiencing a blackout.
- .2%: If the person is still conscious, they will be very confused, unable to follow conversation, need help walking or standing, and likely have trouble seeing or understanding what they see. At this point, most people will pass out, and they are at risk of choking on vomit.
- .25%: Physical and emotional numbness set in, and the person is very likely to pass out. If they remain conscious, they are very likely to injure themselves from stumbling, falling, or other activities. They likely begin to experience alcohol poisoning.
- .35%: This is the level of surgical anesthesia. The person may stop breathing, slip into a coma, and is at risk of death. Oxygen deprivation can damage the brain and the body, including the eyes.
Blurry and double vision are side effects of excessive alcohol consumption, which is typically around the level of binge drinking, or about four servings of alcohol in two hours. While these side effects begin at slightly different points for most people, they typically begin around a 0.08% BAC, and get worse if the person continues to drink.
Another short-term side effect of drinking too much is red or bloodshot eyes. This effect may begin after the person has consumed a few drinks. It happens due to dehydration, leading to dry eyes or changes in blood pressure that widen the blood vessels. Redness in the eyes may persist the next day, especially if the person suffers from a hangover. Another hangover symptom is sensitivity to light, in part due to strain on the eyes from drinking too much.
A sign that a person has consumed too much alcohol includes changes in their eyes’ movement. If a person’s pupils are dilated or do not respond to light, or their eyes move rapidly back and forth in a way they cannot control, their BAC is likely very high, and they are at risk of alcohol poisoning.
While these short-term side effects can be harmful, drinking heavily, binge drinking on a regular basis, or struggling with alcohol use disorder (AUD) for years increases the risk of persistent damage to vision, the optic nerve, and the brain’s processing of visual input.
Alcohol and Eyesight Issues
As a person consumes more alcohol, their liver processes less of the substance, leading to higher levels of toxins in the blood. A buildup of these toxins over time damages many parts of the body, including the optic nerve. Additionally, reduced oxygen intake due to changes in breathing from alcohol can damage sensitive tissues in the body, and the optic nerve is very sensitive to changes. This can lead to macular degeneration, so colors are less vibrant, shapes are fuzzier, and the person begins to struggle with recognizing faces. The American Optometric Association (AOA) notes that excessive alcohol consumption, especially over many years, contributes to age-related macular degeneration (AMD).
Changes in blood pressure reduce how many nutrients and how much oxygen the optic nerve receives, and changes in levels of B12, or thiamine, can also damage vision. Amblyopia is the term used to describe a decrease in vision in one or both eyes, although causes of this condition vary widely; however, excessive alcohol consumption for several years is one known cause of poor eyesight, specifically because of the reduced amount of thiamine available to the body. This is called toxic amblyopia.
Some studies have linked excessive drinking to an increased risk of cataracts. This condition involves a cloudy or opaque area that forms on or near the normally clear lens of the eye. Cataracts may change a person’s vision, and without treatment, they can cause blindness in the eye. Typically, cataracts develop in older adults, those over the age of 55; however, the risk of developing cataracts at a younger age increases with alcohol consumption and associated nutritional deficiency.
There are many reasons to stop drinking, and damage to vision is one of them. Binge drinking, or even just getting one’s BAC up to 0.08%, leads to short-term side effects like double vision or blurry vision, which puts the person at risk of an accident, especially if they drive. Problem drinking and alcohol use disorder put one at risk for long-term damage to the eyes, which can lead to permanent blurry vision, changes to the brain’s ability to process visual input, and even blindness.