The "common misunderstanding" is that methanol does not cause blindness. It certainly can
History: The most significant toxic effects of methanol are optic nerve damage, metabolic acidosis and respiratory depression. Typically within 18 to 48 hours after ingestion, individuals develop nausea, abdominal pain, headache, and slowed breathing. This is accompanied by visual disturbances such as blurred or double vision, changes in color perception, constricted visual fields and complete blindness.
Physical exam: Individuals may experience vision problems, including difficulty seeing clearly, and changes in their field of vision leading to eventual blindness. Individuals may also be fatigued, confused and in a stupor or coma. The abdomen may be tender when palpated, and the individual may experience seizures, cranial nerve palsy, shortness of breath, low blood pressure, slow heart rate, and decreased respirations.
(Source: www.mdguidelines.com/toxic-effects-methyl-alcohol)