This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Alcohol and Alcoholism, Subject name: Forensic Medicine
Methanol causes eye damage by converting into? 
Select and explain. 
A. Formic acid, B. Acetaldehyde, C. Pyridine, D. Acetic acid
A: Formic acid
Answer: A: Formic acid 
Explanation: Ans. is 'a' i.e., Formic acid o Formic acid is the primary agent responsible for the toxic effects and occular complications.o Methanol is metabolized to formaldehyde (by alcohol dehydrogenase) and formic acid (by acetaldehyde dehydrogenase).o It is the accumulation of formic acid which causes toxic effects in methanol poisoning. Accumulation of formic acid results in lactic acidosis/high anion gap metabolic acidosis with low plasma bicarbonates, blindness due to retinal damage, papilledema and optic atrophy.