**Abstract**

Melanin is one of the most stable substances known. The study of the ink bags of fossilized squid that died 160 million years ago has found it in good condition. Its extraordinary stability is what had prevented, to date; assign a relevant role in biology. Sir Everard Holmes' proposal in London; in the eighteenth century, about the role of melanin as a simple sunscreen, it has permeated to this day, especially among dermatologists. Despite the unique physical–chemical qualities of melanin, its biological role as a simple sunscreen that protects us from the dangerous UV rays remained immutable. Our circumstantial discovery during an observational study that lasted 12 years (1990–2002) and which included the ophthalmologic studies of 6000 patients, about the relationship between the vessels of the optic nerve and the three main causes of blindness (Macular degeneration, diabetes, and glaucoma) allowed us to discern the unexpected and surprising true role of melanin in Biology as an energy transducer. The unsuspected intrinsic property of melanin to transform light into chemical energy through water dissociation, like chlorophyll in plants; opens a new era in Biology and therefore in Medicine. And Acute Leukemias are no exception.

**Keywords:** energy, mitochondria, melanin, water, hydrogen, oxygen, ATP
