A total of 19% of those living with sight loss and half of those with severe sight loss have experienced visual hallucinations, a Fight for Sight survey has revealed.

Of those surveyed who have experienced visual hallucinations, 20% said it impacted their mental health, four in 10 said it affected their ability to go about daily life and 35% said hallucinations had got worse during the pandemic.

The charity said that Charles Bonnet syndrome (CBS) was a common but little-know side effect of sight loss and could cause clear, detailed and consistent hallucinations.

In partnership with Blind Veterans UK, Esme’s Umbrella and Health and Care Research Wales, Fight for Sight has funded two projects to investigate the cause of the visual hallucinations associated with CBS.

One study will investigate the possibility that peripheral vision is more suggestible than central vision and the second study will use a type of MRI scan to measure the levels of chemicals in the visual areas of the brain to see whether they are abnormal in people with CBS.

Sherine Krause, chief executive of Fight for Sight, said: ‘With a better understanding of the causes of CBS, we will be one step closer to developing a treatment and cure for the condition. However, more investment in eye research is needed to ensure we can continue transforming the lives of people with sight loss.’