UCL News


Visual hallucinations among blind people increase during pandemic

12 February 2021

People with Charles Bonnet Syndrome, which involves visual hallucinations for people who have lost their sight, have had worsening symptoms during the pandemic, finds a study led by UCL researchers.


The study of 45 patients from Moorfields Eye Hospital between June and July 2020, published in BMJ Open Ophthalmology, reports of harrowing increases in symptoms in over half of participants.

The findings highlight that social isolation, loneliness, lack of exercise and exposure to distressing media over the COVID-19 lockdown have exacerbated and intensified visual hallucinations in 56% of the patients studied.

Lead researcher Professor Mariya Moosajee (UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust) said: “I had been trying to raise awareness of this condition pre-COVID; it can affect any one with sight loss ranging from young children to the elderly. COVID has impacted every single one of us, but now we have evidence that social isolation is precipitating a scary complication of visual impairment, which may have a major long-term effect on mental health.”

Charles Bonnet Syndrome (CBS) is not curable but there are techniques to manage the condition as well as support. The study’s researchers say that, where possible, increasing social interactions and engaging in physical exercise could help to reduce hallucinations. They say that an increase in healthcare professionals being aware of CBS risk factors is vital to diagnose more effectively. This leads to better strategies to promote patients being able to manage their condition.

The study publication coincides with increased public discussion of CBS, as an established character on Coronation Street, Johnny, began to hallucinate due to his sight loss from optic neuritis. In this week’s episode, the character is scared, isolated and afraid that people think that he is ‘going mad’.

Esme’s Umbrella, the UK’s CBS campaign has been working tirelessly since it was founded by Judith Potts in 2015 to raise awareness of the condition. Potts, who is a co-author on the researcher paper, said: “Sadly it is often overlooked as a mental health condition or otherwise and is therefore not managed effectively. I am so pleased that our voice is now being heard and the horror of the condition is being recognised not only on national TV but also in this latest study.

“My dream is that anyone experiencing CBS will not be afraid to go to their doctor and when they do, they will be diagnosed quickly. COVID-19 has added to the situation in negative way as highlighted in the study.”

The study was supported by the NIHR Moorfields Biomedical Research Centre, Thomas Pocklington Trust and Wellcome.

Another study by a UCL researcher, published last month, found that the visual hallucinations experienced by people with CBS can stem from spontaneous activity in the brain’s visual centres.*




Media contact

Chris Lane

Tel: +44 (0)20 7679 9222

Email: chris.lane [at] ucl.ac.uk