• charles bonnet syndrome

In his paper on page 518 of this issue, Dr Eric Nieman describes his medical journey of a progressive visual deterioration due to glaucoma, accompanied by the gradual development of increasingly distressing visual hallucinations - the Charles Bonnet syndrome.

The eponym was coined by de Morsier in the 1930s, in recognition of Charles Bonnet (1720–1793), a renowned Genoese naturalist, philosopher and biologist, who in 1769 described the hallucinatory experiences of his grandfather Charles Lullin, a 89-year-old magistrate. Lullin described his subjective perception of visions of people, animals, and buildings of various shapes and sizes, associated with visual deterioration after bilateral cataract surgery. He had normal cognition and realised his visions were ‘fictions’ of his brain.1

Charles Bonnet syndrome occurs predominantly in elderly, visually impaired people. Around 11%–15% experience complex visual hallucinations, whereas a significantly greater number, between 41%–59%, experience elementary visual phenomena. Such individuals do not have psychological or cognitive …