I just had a quick browse for you and some people have said it could be from wearing glasses for many years [although i dont know why other than maybe stopping you catching the sun as much there???], it might be due to some creams or lotions you've applied on the area and caused the white spot, it can be a layer of dead cells, applying to much concealer to the area can cause it because of the amount of titanium and Zinc oxide in them, it could also even be an indication of intolerance of dairy products, or it could just be a superficial fungus or excema. Now its just figuring out which one it is :s.