I Had Head And Neck Cancer. Less Than 2mm Spot

I had head and neck cancer. Less than 2mm spot on base of tongue and lymph nodes on right side of neck. 35 radiation treatments ended Feb 18, 2015. 4 rounds of chemo from Dec 2014 to Jan 2015. Given the "all clear" Oct 2015. Problem is seeing things that aren't there in peripheral vision. Is this "normal" and is it temporary?