Can a large eye floater affect peripheral vision in a visual field test.

No expected: No. This would not seem to be an expected dynamic. Is this what you were told or is this your idea? I am not an opthamologist and we will have to see if one has an opinion about this matter. I will ask for a consult for you.

Yes: Visual field testing will occasionally pickup small areas of visual field depressions if the floater is particularly large and thick, as some patients may have. Since they move, a repeat visual field should also show the depression to have moved. I would not however expect a large visual field abnormality from a floater and certainly l recommend an exam to rule out any problems by an eye md.