Vision loss is typically the only symptom of LHON. However, in some cases additional signs and symptoms have been reported. In these people, the condition is known as ‘LHON plus’. Non-visual symptoms associated with LHON plus can include muscle problems.

Some people develop features similar to multiple sclerosis, with muscle weakness and poor coordination. This can also be called Harding’s disease and is more common in females.

More information about LHON plus can be found on the LHONPlus website.