Could what I am calling a loss of pixels in vision be related to a brain tumor. I have had all the eye test with no diagnosis. Loss of a field of vision in r eye, even seen a retina specialist and said it isn t in the eye. MRI shows a small vascular malformation in the occipital lobe. I am having bouts of vertigo, no specific time or events that sets them off. When I have the vertigo I lose vision completely and experience intense rise in body temperature.