Hi byterbit

Welcome to NeuroTalk .

I think that what you have described is technically called hemianopsia.

The most common causes of it are a stroke, a tumour or traumatic brain injury.

The information in these links might help you to discuss this with your health care team.

Hemianopsia | Definition and Patient Education

http://www.visionaware.org/info/your...ons/stroke/125

All the best.