Visual field defects are a common consequence of acquired brain injuries and affect people of all ages. These vision problems make everyday life more difficult-for example, when reading, driving, or moving around safely. However, there is currently no effective therapy to improve visual field defects. Previous training methods have focused on maximizing brain activity during a task. However, new findings show that the best performance is achieved when the brain is already in a state of high communication before the task. Our research shows that people can learn to increase communication between brain regions through neurofeedback. Studies have shown that neurofeedback can help people after a stroke: it improves the coordination of brain areas that are important for movement, thereby helping to increase mobility. Building on these findings, this study investigates whether EEG neurofeedback can support the visual centers in the brain to improve vision in patients with chronic visual field defects. The main objective of the study is to evaluate the effectiveness of neurofeedback in improving visual field defects. More specifically, the investigators are investigating the development of visual ability (expansion of the visual field, contrast sensitivity).