ok, first of all あなた should learn what ocular albinism is when the eyes lack in pigment often causing them to be blue. it can also impair vision によって causing someone to be near または far sighted, and/or not be able to focus correctly on something.
hints of ocular albinism in Simon.
Simon shows a lesser pigment in eye coloring (his eyes are blue)
he also has glasses 表示中 that he can not focus well on stuff
he may be farsighted because in the 移動する (Alvin and the chipmunks) Dave holds up 2 fingers and asks Simon to count them. he gos to guess 5 times before choosing 6.