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Alcohol affects the eyes in the short and long term. Short-term effects include blurry vision, slow pupillary response, dryness, double vision, and redness. Long-term effects, such as increased risk of cataracts, macular degeneration, and optic nerve damage, can eventually lead to vision loss. The effects after a night out are usually temporary. Yet, the long-term effects of heavy drinking are a different story. If you’re experiencing persistent symptoms, call Miami Contact Lens Institute to schedule a comprehensive eye exam.
What Does Alcohol Do to Your Eyes?
Alcohol affects both your eyes and the way your brain processes vision. It can temporarily slow communication between the brain and the eye muscles, reduce tear production, and make it harder for your eyes to work together. Heavy, long-term alcohol use can also increase the risk of serious eye disease.
The National Institute on Alcohol Abuse and Alcoholism defines heavy drinking as four or more drinks in a day or eight or more in a week for women. And five or more drinks in a day or 15 or more in a week for men.
Binge drinking means consuming that amount in about two hours. Even if someone doesn't have an alcohol use disorder, regularly drinking large amounts of alcohol or drinking alcohol every day increases the risk of long-term eye damage, alcohol dependence, and other health problems.
Short-Term Effects of Alcohol on Your Eyes
Drinking even small amounts of alcohol can affect your eyes in several ways. When combined with the effects that alcohol has on the brain, cognition, and reaction time, it’s easy to see why drinking and driving is so dangerous. Let’s explore the immediate effects:
Blurry or Double Vision
Due to slowed brain-eye communication and poor muscle function, blurred vision and double vision (diplopia) are common. In Florida, the blood alcohol content (BAC) threshold for driving is 0.08g per 100 milliliters of blood. Depending on your body weight and biological sex, you may meet or exceed the threshold after two to four standard drinks. A standard drink is around 12 oz of beer, five oz of wine, or 1.5 oz of spirits, depending on the percentage of ethanol in the drink.
Slower Pupillary Response
Pupils constrict and dilate more slowly after drinking alcohol, so eyes cannot adapt to oncoming headlights fast enough. This means that if an oncoming car has its headlights on at night, it can effectively blind you for a short time while your eyes adjust. Even a few seconds of vision loss can lead to serious accidents, especially at high speeds.
Reduced Contrast Sensitivity and Night Vision
Your ability to distinguish between light and dark is reduced significantly by alcohol. Many people see halos and starburst patterns in low-light scenarios. According to a study done by Kevin Johnston and Brian Timney from the Schulich School of Medicine & Dentistry, the ability to process the differences in brightness and contrast is reduced by about 30% at a BAC around the legal driving limit.
Bloodshot or Red Eyes
Drinking alcohol initiates a process called vasodilation, where the blood vessels in the eyes dilate and fill with more blood, making them appear red. Alcohol is also a diuretic, which means that it causes the body to lose water rapidly. The overall dehydration leads to irritation and inflammation, which also contribute to red eyes.
Dry Eyes
Alcohol dehydrates the body and destabilizes the tear film, which is made up of a delicate balance of water, oil, and mucus. When the watery component of the tear film is compromised, eyes become dry, itchy, and painful. There are several treatments available for chronic dry eye, which can develop as a result of habitual heavy drinking. If alcohol contributes to ongoing dry eye symptoms, your eye doctor may recommend treatments such as artificial tears, prescription medications, or procedures like intense pulsed light (IPL) depending on the underlying cause.
Eyelid Twitching (Myokymia)
Myokymia is an involuntary twitching of the eyelid muscle, usually the lower lid. Alcohol is a common trigger, alongside excessive caffeine, stress, and lack of sleep. Myokymia typically resolves on its own when the cause is addressed. If you experience chronic eye twitching, reach out to your eye care specialist to identify any potential underlying conditions.
Involuntary Eye Movements (Nystagmus) and Sobriety Tests
The horizontal gaze Nystagmus (HGN) test is one of three field sobriety tests performed when a police officer suspects drug or alcohol impairment. The test measures involuntary eye movements called nystagmus. Alcohol triggers nystagmus and is one of the most recognizable symptoms of intoxication.
Long-Term Effects of Heavy Drinking on Eye Health
Over time, heavy drinking can have a significant negative impact on eye health. Chronic alcohol abuse can permanently damage the optic nerve, leading to severe side effects, including:
Cataracts
The National Library of Medicine studies show that moderate alcohol consumption, defined as less than 20g of alcohol per day, causes an insignificant increase in cataract risk. On the other hand, heavy alcohol consumption, defined as a daily intake of 20g of alcohol, or 140g per week, is associated with a significant increase in the risk of cataract development.
Age-Related Macular Degeneration
Excessive alcohol consumption increases the risk of age-related macular degeneration (AMD). The macula is a small part of the eye that is responsible for sharp central vision, allowing you to clearly see fine details, colors, and faces. AMD is a progressive condition that damages the macula, leading to blurry vision or central vision loss.
Optic Neuropathy
Optic neuropathy refers to damage to the optic nerve, which transmits signals from the eye to the brain. Habitual heavy drinking increases the risk of developing optic neuropathy, which causes sudden or gradual vision loss, blind spots, and reduced color vision. Optic neuropathy is typically painless, so many patients don’t realize it’s happening until their vision is affected.
Vitamin Deficiency and Vision Loss
Drinking alcohol impairs vitamin absorption, which can have catastrophic consequences for the eyes. Vitamin A deficiency leads to night blindness, corneal thinning, and retinal damage. B1/Thiamine deficiency results in eye-muscle weakness or paralysis. B-vitamin deficiencies also contribute to nerve damage and eventual vision loss.
Jaundice and Liver Disease
The sclera is the white part of the eye, and with chronic heavy drinking, it can become yellow, indicating liver cirrhosis. Changes in the eyes can sometimes be an early sign of underlying health conditions, which is one reason regular comprehensive eye exams are so important. Regular eye exams are a crucial part of full-body health, as any issues can be identified and addressed immediately.
Prenatal Alcohol Exposure
Alcohol use during pregnancy can permanently alter a baby’s visual development. Optic nerve underdevelopment, coordination problems, and drooping eyelids are common in children who were exposed to alcohol in the womb. All doctors agree that drinking alcohol while pregnant is very risky. Many believe that those trying to conceive should stop drinking alcohol even before falling pregnant to further reduce the chance of harming the fetus.
Does Alcohol-Related Vision Damage Go Away?
The short-term effects of alcohol on the eyes go away as the alcohol leaves your system, but the effects of long-term chronic alcohol consumption aren’t always reversible even if you choose to become sober.
Alcohol, Dry Eye, and Contact Lens Wearers
As discussed, alcohol can cause severe dry eye, which can lead to serious complications for contact lens wearers. Being dehydrated makes lens wear uncomfortable and can cause painful friction with every blink. You should never sleep with contact lenses in, but it is even more crucial to remove lenses before sleep if you have consumed alcohol to prevent intense dry eye. If you plan on drinking alcohol, consider wearing your glasses instead of contact lenses for the evening, especially if your eyes tend to become dry or irritated.
When Should You See an Eye Doctor?
You should see an eye doctor after drinking if you have vision changes that persist after sobering up, persistent redness and pain, yellowing eyes, and reduced night vision quality. If you experience sudden vision loss, seek emergency eye care immediately. At Miami Contact Lens Institute, we provide comprehensive eye examinations that can detect the early signs of cataracts, macular changes, and optic nerve disease.
Many alcohol-related vision changes are temporary, but persistent symptoms should never be ignored. A comprehensive eye examination can help determine whether there's an underlying eye condition that needs treatment.
Schedule an Eye Exam at Miami Contact Lens Institute
If alcohol-related vision changes persist after you've sobered up, don't ignore them. At Miami Contact Lens Institute, we can evaluate your eye health, identify any underlying problems, and recommend the most appropriate treatment to help protect your long-term vision. Schedule a comprehensive eye examination today.
Frequently Asked Questions
Can alcohol cause blindness?
Alcohol can cause blindness, either through acute alcohol poisoning or gradually through chronic long-term alcohol use disorder. Consuming bootleg, illegally distilled, or counterfeit alcohol can cause immediate, permanent blindness within 48 hours. Never drink alcohol if you don’t know where it came from.
How long after drinking does vision return to normal?
Usually, alcohol-related vision issues return to normal within 12 hours of your last drink. Full recovery does, however, depend on the amount of alcohol you drank, your hydration levels, and your individual metabolism. Some physical signs, like bloodshot eyes and dry eyes, can take up to 72 hours to resolve.
Why is my vision blurry after drinking?
Alcohol is a central nervous system suppressant, so it slows the communication between your brain and eye muscles. This results in a temporary loss of coordination, reduced ability to focus, and dehydration.
