Fig. 4: The ‘Peekaboo’ app is an example of how technology for visual testing could be used to help treatment of visual loss.

Observing saccades towards the striated target enables examiner and carer to infer the patient has seen it, even if the patient reports they do not see it. In addition, the patient can be asked to guess where the target is by touching the screen even when they can’t see it. This can help gauge/ prove to the patient whether their ‘brain’ can still see, even if they don’t have visual experience.