How Does Methanol Cause Blindness? (Explained!)

Methanol (or methyl alcohol) is an alcohol commonly found in industrial solvents, including antifreeze, carburetor fluid, and canned fuels. It is hazardous and toxic. The chemical composition of methanol is CH3OH making it the shortest chain and therefore simplest alcohol.

Methanol is particularly dangerous because it can be challenging to detect. It’s odorless and colorless, so it’s not always obvious when it’s present. And, unlike ethanol (the type of alcohol found in beer, wine, and liquor), the body metabolizes methanol differently. When ingested, methanol is converted into formaldehyde and then to formic acid, leading to blindness and death.

How much methanol does it take to go blind?

As little as 4ml (about two tablespoons) can cause vision problems or cause blindness. Also, as little as 60 ml has caused death, although lethal doses typically are a small amount more, between 70 ml to 100 ml.

How does methanol cause blindness?

When methanol is ingested into the body, it is converted to formaldehyde. It then produces formic acid, which turns the blood more acidic in the body. It affects the optical nerve on a cellular level and interrupts the mitochondrial function in the optic nerve. Methanol poisoning can cause blindness by damaging the optic nerve. Formic acid, produced when the body metabolizes methanol, can build up and damage the optic nerve. This damage can lead to vision problems and even blindness.

How does methanol cause death?

Methanol poisoning can cause death by damaging the liver or by causing seizures. Formic acid, produced when the body metabolizes methanol, can build up and damage the liver. This damage can lead to liver failure and death. Seizures caused by methanol poisoning can also be fatal.

What are the symptoms of methanol poisoning?

The symptoms of methanol poisoning depend on how much methanol has been ingested. Symptoms can appear as quickly as 30 minutes after ingestion or may not appear for several hours.

Initial symptoms may include:

• · Headache
• · Dizziness
• · Nausea
• · Vomiting
• · blurred vision

If not treated, methanol poisoning can lead to more severe symptoms, including:

• · Seizures
• · Coma
• · Kidney failure
• · Liver failure

How many people go blind from drinking methanol each year?

There are no official numbers on how many people go blind from drinking methanol each year. 

Is methanol-induced blindness reversible?

If you go to the hospital after experiencing methanol-related blindness, drinking whiskey or some other type of hard alcohol may be an unexpected cure is to drink whiskey or some other type of hard alcohol. The body prefers to metabolize ethanol (regular alcohol) rather than methanol. This may stop blindness in its tracks.

Yes, if methanol poisoning is detected early, blindness can be reversed. Even after some time, there are various methods to reverse the condition.

Intravenous ethanol treatment, along with hemodialysis, is also effective between 3 to 93 hours after ingestion of methanol.

There are a variety of other treatments that work along a similar pathway of repairing formic acid toxicity. These treatments must be started as soon as possible for the best chance of success, with the best results within a few hours and after permanent damage may occur. 

How can I avoid methanol poisoning?

The best way to avoid methanol poisoning is to be aware of the dangers and take precautions. If you suspect that you or someone else has ingested methanol, seek medical attention immediately. Be sure to inform medical professionals how much alcohol was consumed and when.

If you are distilling your alcohol, use proper safety equipment, including a gas mask, to avoid inhaling methanol fumes. Also, be sure to dispose of any waste.