Leber hereditary optic neuropathy (LHON) is an inherited form of vision loss that causes people to have trouble with their colour vision and difficulty seeing in the centre of their visual field. Due to the founder effect from the filles du roi, there is a disproportionate preponderance of a particular LHON mutation among the French-Canadian population.
Until recently, researchers believed the cause of LHON was related to the size of the fibers that connect the eye to the brain, with small fibers being more sensitive. However, it wasn’t clear how exactly the two were connected.
Read more at McGill University