# It Is All One-Sided: Monocular Blindness and Charles Bonnet Syndrome

## TL;DR

A 72-year-old man with monocular blindness experienced Charles Bonnet Syndrome, showing it can occur in one eye and is underdiagnosed.

## Contribution

This case highlights that Charles Bonnet Syndrome can occur in monocular blindness, challenging the conventional view of bilateral vision loss.

## Key findings

- Charles Bonnet Syndrome can manifest in monocular blindness.
- Monocular cases of CBS are underdiagnosed in current literature.

## Abstract

We present the case of a 72-year-old male who developed Charles Bonnet Syndrome (CBS) following a right retinal artery occlusion.

Complex visual hallucinations are the main symptom of CBS in persons with substantial vision loss. It has been conventionally associated with bilateral severe impairment, but recent observations indicate under-recognised monocular cases that offer equally notable incidences of CBS.

This case highlights the importance of recognising that CBS can also occur in monocular blindness and its underdiagnosed prevalence in current literature. In order to avoid the misidentification of CBS in unilateral vision loss and to empower patients with information and empathy, increased focus on recognising monocular CBS and providing targeted guidance for patients is required.