How Can Drinking Too Much Cause You To Go Blind?

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Dec. 4 2012 6:34 PM

Can You Really Drink Yourself Blind?

Bonus: Can you cure yourself by drinking even more?

man and woman enjoying a drink.
For the sake of your optic nerve, beware what you drink

Eyecandy Images/Thinkstock.

A New Zealand man recently went blind after drinking lots of vodka while on diabetes medication. Thankfully, doctors were able to restore his sight by administering him Johnnie Walker Black Label whiskey. Can you really drink yourself blind?

Forrest Wickman Forrest Wickman

Forrest Wickman is a Slate staff writer. 

If you’re drinking moonshine, yes. Although alcohol that’s properly manufactured and regulated does not by itself cause blindness, people sometimes do go blind from drinking bootleg beverages. One common concern with moonshine is lead poisoning, which has been linked to blindness. Since moonshine is unregulated, it has sometimes been manufactured using lead pipes, lead soldering, or even car radiators, which can contain high levels of lead. A 2003 study found that more than half of moonshine drinkers have enough lead in their bloodstream to exceed what the CDC calls a “level of concern.” However, most manufacturers of moonshine these days are aware of this danger and will avoid using lead in their distilling process.

Today the most common cause of blindness from drinking is methanol. Methanol, otherwise known as methyl alcohol or wood alcohol, can damage the optic nerve and even kill you in high concentrations. During Prohibition, bootleggers were known to sell moonshine that contained methanol, and the practice continues abroad. Some bootleggers add methanol in order to increase the hooch’s potency or to mask when it’s been watered down. (Methanol has a strong taste and smell, though with modern manufacturing methods it’s not always as noticeable as it was before the 20th century.) Some people will drink products that contain methanol—including antifreeze, paint thinner, and other denatured alcohol products—in pursuit of a cheap buzz. As little as 4 milliliters of methanol has been known to cause blindness, and as little as 30 to 60 milliliters has been reported to kill drinkers. A more common lethal dose would be 70 to 100 milliliters. A 1922 report by the National Committee for the Prevention of Blindness documented that during the first half of that year, wood alcohol caused 130 deaths and 22 cases of blindness, though the group warned that there must have been many more cases that were hidden from authorities.

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Methanol continues to cause occasional outbreaks of blindness among moonshine-drinkers abroad. In 1989, the New York Times reported that 125 people died in India after drinking moonshine. Many victims complained of blindness among other symptoms after drinking the illegal booze but avoided going to the hospital for fear of being arrested. In 2011, several Russian tour guides were killed after consuming bootleg alcohol on a trip through Turkey, and police reportedly found methanol in the whiskey sold on the yacht. In September, the Czech government became concerned with bootleg liquor after cheap methanol-tainted spirits left 20 people dead and at least one man blind.

The phrase blind drunk doesn’t derive from either methanol- or lead-related blindness. According to the Oxford English Dictionary, the phrase has been used for more than 350 years to refer to the more figurative meaning of being “so intoxicated as to see no better than a blind man.” (The Spanish ciego, for blind, can also be used to mean “very drunk.”) Similar phrases, including blind-weary and blind-hearted, have been used in English for about a millennium.

Bonus Explainer: If you drink yourself blind, can you really be cured by drinking whiskey? Yes. Methanol poisoning occurs when your body metabolizes dangerous quantities of methanol, resulting in too much acid in the blood. This acid can then damage or kill cells in the optic nerve. However, the body prefers ethanol (regular drinking alcohol) to methanol, so drinking whiskey or other unadulterated liquor can help prevent the body from metabolizing more methanol. No one who suffers from methanol poisoning should self-medicate with whiskey. If you suspect you’ve consumed methanol, you should call poison control immediately. But if you go to the hospital, don’t be surprised if the doctor tries to cure you with a few shots of the hard stuff.

Got a question about today’s news? Ask the Explainer.

Explainer thanks Matthew Rowley, author of Moonshine!, and Gaylord Lopez of the Georgia Poison Center.


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