There's a terrible hereditary eye disease called Leber's hereditary optic neuropathy that affects men in their twenties. It's a mitochondrial disease inherited from your mother that leads to total blindness within six months of onset.
A recent breakthrough from a team of researchers at Newcastle University suggests this disease may be reversible in its early stages. The researchers gave 55 test subjects the drug idebenone for six months and 20 reported an improvement in their vision at the end of the study.
It didn't work for everyone and it's not a cure, but as team leader Patrick Chinnery points out the results show the drug had "a significant effect." Best of all, idebenone has limited side effects and could be used prophylactically to prevent the onset of the disease. The same treatment could also be used to treat other mitochondrial diseases as well. [New Scientist]