Answer transcribed from Brightway's Interview with Dr. Bryce Appelbaum: 

Vision is very much intimately woven throughout the entire brain and because it's represented in every lobe of the brain. The visual pathways that allow us to use peripheral vision start at the eyes and go all the way back. So depending on where an injury is or especially with any type of surgical intervention, it's really hard to miss vision and then not allow periphery to be impacted. I think for most cases under stress, particularly under visual stress, we try to control a world that's under some disorder. Oftentimes that can be being overly focal or overly central in our visual processing and less aware of the peripheral. Sometimes if it's a structural issue, we don't have access to the nerves that allow us to see periphery then that's not somebody who's going to be amenable to rehabilitation. However, if it's a matter of raising a peripheral awareness and becoming more aware of what's in front of us simultaneously with what's on the sides, that can be very effective.

There's not a whole lot of good research on visual field defects being improved the way in. With vision therapy, the way that we actually see in clinical practice and by forcing the brain to access areas of the periphery that are desensitized or not tapped into, we can literally almost massage those areas of the field by arranging the conditions with the right type of equipment where we can access areas that are being ignored. If in fact, we can tap into those, though I would say it's rare to find somebody where we can't enhance periphery, I think the key would be finding the areas of life or the activities of daily living that are impacted and then map out how we tailor therapy to those specific areas. I think the big thing is, you mentioned frontal lobe damage, that's where a lot of our eye movements originate from. So I would imagine there are probably some challenges with eye movement control and maybe even inattention or ADD/ADHD-like behavior because any change in eye movement is a change in attention whether that's voluntary or involuntary. If we can't control our eye movements, how can we possibly control our attention? So I do think knowing where something's located in our periphery accurately makes the right eye movement. To get there is something that usually can be improved for most people but I think to answer that question, it kind of depends on the tumor that was removed and how much of the brain has been altered obviously for means that were necessary.