LHON is the most common mitochondrial optical neuropathy with a prevalence of ~1 in 50,000 people (6,500 people in the U.S.). LHON is a mitochondrial neurodegenerative disease, most commonly diagnosed in young males between the ages of 25-35. It is characterized by a loss of central vision due to dysfunction and loss of retinal ganglion cells.  In most cases, symptoms begin with one eye, followed by visual failure in the other eye within several weeks or months.