Beer Consumption: Blindness Risk And Visual Health

Drinking beer will not make you blind, but excessive alcohol consumption can lead to permanent vision damage and even blindness in some cases. While properly manufactured and regulated alcohol does not cause blindness, people have been known to go blind from drinking bootleg beverages, such as moonshine, which may contain methanol, or wood alcohol, which can damage the optic nerve. Consuming even a small amount of methanol can be fatal.

Optic nerve damage

The optic nerve is responsible for transmitting visual information from the eye to the brain. Optic neuropathy refers to a lesion or loss of functionality in the optic nerve, which can be caused by various factors, including toxic substances like alcohol. While ethanol is the type of alcohol typically found in alcoholic beverages, it is sometimes replaced with methanol in bootleg beverages, which can immediately damage the nervous system, including the optic nerve. As little as 4 millilitres of methanol has been known to cause blindness.

Alcohol abuse is often associated with nutritional and vitamin deficiencies, which further contribute to optic nerve toxicity. The main symptom of optic neuropathy is painless and progressive loss of vision, starting with blurriness in the central visual field, followed by reduced visual acuity. The damage to the optic nerve can be severe and may result in permanent loss of vision if alcohol consumption is not stopped early.

In addition to methanol poisoning, heavy drinking can also lead to toxic amblyopia or vision loss. The excessive consumption of alcohol affects the optic nerve and disrupts the relationship between the brain and the eye. This can result in involuntary eye movement, double and distorted vision, and impaired ability to see different colour shades or adjust to lighting differences.

Methanol poisoning

Drinking beer will not make you go blind. However, methanol, a toxic alcohol found in various household and industrial agents, can cause blindness.

Methanol (CH3OH) is a toxic alcohol that can be found in windshield washer fluid, gas line antifreeze, carburetor cleaner, copy machine fluid, perfumes, food-warming fuel, and other types of fuels. It is also sometimes added to moonshine by less-than-reputable distillers. It is extremely dangerous, and if left untreated, can lead to significant morbidity and mortality.

Symptoms

Initial symptoms of methanol intoxication include central nervous system depression, headache, dizziness, nausea, lack of coordination, and confusion. As little as 10 mL of pure methanol when drunk can cause permanent blindness by destruction of the optic nerve. Blindness may occur as early as 12 hours after exposure. Other symptoms include:

• Decreased level of consciousness
• Poor or no coordination
• Vomiting
• Abdominal pain
• A specific smell on the breath
• Blurred vision
• Photophobia
• "Snowstorm vision" or complete loss of vision
• Acidosis
• Putaminal hemorrhages
• Tachypnea
• Dilated pupils
• Hyperemia of the optic disc
• Retinal edema

Treatment

The primary treatments for methanol poisoning are either ethanol or fomepizole, and dialysis is often recommended. Folate administration may also be beneficial as it may enhance the metabolism of formate, a toxic metabolite of methanol.

Alcohol's effect on the brain

Alcohol can have a significant impact on the brain, affecting both its structure and function. Here are some key ways in which alcohol can affect the brain:

Interference with Brain Function

Alcohol interferes with the brain's communication pathways and can affect how the brain processes information. It impairs the areas of the brain that control balance, memory, speech, and judgment, leading to a higher likelihood of injuries and other negative outcomes. This interference can cause a range of short-term effects, such as double vision, blurriness, and difficulty adjusting to brightness and light contrasts.

Alterations in Neurons

Long-term heavy drinking can lead to alterations in neurons, including reductions in their size. This can result in changes in brain structure and function, compromising normal brain activity.

Alcohol-Induced Blackouts

Alcohol misuse can cause blackouts, which are gaps in a person's memory of events that occurred while they were intoxicated. These occur when alcohol blocks the transfer of memories from short-term to long-term storage in the hippocampus region of the brain.

Increased Risk of Brain Damage

Excessive drinking over an extended period can lead to lasting brain damage. This damage can manifest in various ways, including mental health issues such as depression and anxiety, as well as severe and potentially permanent cognitive deficits.

Wernicke-Korsakoff Syndrome (WKS)

Alcohol abuse can lead to WKS, a brain disorder characterized by amnesia, extreme confusion, and eyesight issues. WKS is caused by a thiamine (vitamin B-1) deficiency, which can be induced by alcohol consumption.

Prenatal Alcohol Exposure

Alcohol consumption during pregnancy can cause fetal alcohol exposure, resulting in brain damage to the developing fetus. This can lead to a range of developmental, cognitive, and behavioral problems that can manifest at any time during childhood.

Optic Nerve Damage

Consuming certain types of alcohol, such as methanol, can damage the optic nerve and lead to blindness. Methanol is sometimes added to adulterated or bootleg alcohol, posing a significant risk to consumers.

Long-term effects on the eyes

While a small amount of alcohol in moderation will likely not cause any problems, long-term excessive drinking can permanently damage your eyesight and can even lead to blindness in some cases. Here are some of the long-term effects on the eyes:

• Brain-to-Eye Communication: Alcohol affects the brain, and because the brain and eyes are so closely linked, our vision suffers as a result. When someone spends a night drinking too much, the brain has trouble communicating with the eyes. The images being sent from the brain to the eyes are not being interpreted correctly or take longer to process. This slowed communication can not only affect how we interpret images but can also cause a myriad of other side effects that will impair your vision and, in some cases, even damage your eyes.
• Optic Nerve Damage: The optic nerve is made up of neurological transmitters, which can be damaged by alcohol consumption, just like in the brain. The optic nerve is responsible for sending impulses from the retina of the eye to the brain. Damage to the optic nerve can lead to low vision and sometimes blindness. Optic nerve damage can also be very painful, leading to eye pain, eye floaters, loss of vision in one or both eyes, and loss of colour perception.
• Rapid Eye Movements: While rapid eye movements are normal during sleep, they are rare and unusual when we are awake. Excessive drinking can cause involuntary rapid eye movements, known as nystagmus, which can affect one or both eyes. These involuntary movements can cause your eyes to jump randomly, making it difficult for them to focus on one point for an extended period. Constant jumping around can also lead to eye strain and headaches.
• Double Vision: Double vision is a common vision problem associated with excessive drinking and is caused by diminished communication between the eyes and the brain. While it is usually not dangerous, it can lead to a loss of depth perception, making walking and other tasks difficult.
• Bloodshot Eyes: Alcohol reduces oxygen to red blood cells, causing blood vessels to clump together and resulting in red, bloodshot eyes. This condition usually goes away after a night of drinking, but if it persists, it may require medical attention.
• Cataracts: Multiple studies have shown an increased formation of cataracts in patients with higher alcohol consumption.
• Age-Related Macular Degeneration (AMD): Damage to the retina from long-term excessive alcohol consumption can result in vision loss in the centre of the eye.
• Vitamin Deficiency: Heavy drinking affects the absorption of vitamins in the liver, which are necessary for maintaining healthy eyesight. For example, a vitamin B-1 deficiency can cause weakness or paralysis of the eye muscles, while a vitamin A deficiency can lead to night blindness, thinning of the cornea, corneal perforation, dryness, and even blindness due to retinal damage.
• Optic Neuropathy: Excessive drinking can lead to optic neuropathy, a serious condition that can result in complete and permanent loss of eyesight, also known as tobacco-alcohol amblyopia or toxic amblyopia.
• Dry Eyes: Alcoholic beverages are diuretics, which increase urine flow and contribute to dehydration. As a result, people often wake up with dry, irritated eyes after a night of drinking. This effect is especially pronounced in those who already suffer from dry eye syndrome.
• Loss of Contrast: Alcohol decreases the reactions of the pupils, affecting their ability to constrict or dilate correctly in response to changes in light. This impairs the eye's ability to detect contrasts between colours and shades, which is important for activities such as driving or playing sports.
• Increased Toxin Levels: Excessive drinking can lead to increased toxin levels in the blood, as the liver is unable to process alcohol effectively. These toxins can damage the optic nerve and contribute to vision loss.

Short-term effects on the eyes

Drinking beer or any other type of alcohol can cause several short-term effects on your vision. Here are some of the ways that alcohol can impact your eyesight in the short term:

Double vision

Alcohol can cause distorted or double vision, also known as "beer goggles." This occurs due to poor coordination in the eye muscles, which is a result of slowed communication between the brain's neurotransmitters and the body.

Blurred vision

Alcohol consumption can lead to blurred vision, especially at night. This is often associated with impaired colour perception, making it difficult to distinguish between different colours and shades.

Difficulty adjusting to light

Alcohol decreases the reaction of the pupils, affecting their ability to constrict or dilate properly in response to changes in lighting conditions. This can make it challenging to adjust to different levels of brightness and light contrasts, such as when moving between dark and light rooms.

Twitching eyelids

Alcohol can stimulate the eye muscles and cause myokymia, which is characterised by twitching eyelids.

Dry eyes

Beer, wine, cider, and spirits are diuretics, which increase urine flow and contribute to dehydration. As a result, you may wake up with dry and irritated eyes. Alcohol can worsen dry eye syndrome, especially for those who already suffer from this condition.

Red eyes

Alcohol reduces oxygen to red blood cells, causing blood vessels to clump together, which can result in red, bloodshot eyes.

It is important to note that most of the short-term effects of alcohol on the eyes will go away on their own. However, excessive drinking over a long period can lead to more severe and permanent vision problems.

Frequently asked questions