The question relates to the substance in liquor that can lead to tragedies like blindness when consumed. The four options represent different types of alcohol.

Option 1, ethyl alcohol, is the type of alcohol found in alcoholic beverages like beer, wine, and spirits. It`s the substance that makes you feel "drunk" but it doesn`t lead to blindness.

Option 2, amyl alcohol is a type of alcohol that is used in the production of chemicals and is not typically found in consumable alcoholic beverages.

Option 3, benzyl alcohol, is a type of alcohol that is generally used as a solvent in a variety of industries and isn`t typically found in drinkable alcohol.

Option 4, methyl alcohol, is the correct answer. Methyl alcohol, also known as methanol, can lead to significant health issues such as blindness and even death if ingested. While it`s commonly used in industry (for example, as a solvent or antifreeze), it should never be consumed. It becomes harmful when it is metabolised in our body into formaldehyde and formic acid, which can attack the optic nerve and potentially cause blindness.