the color of the eye is determined by the ammount of pigmentation present in the iris. technically, it is possible to change eye color if you can introduce an agent that will inhibit melanin creation in the form of eye drops.
"Changes (lightening or darkening) of eye colors during puberty, early childhood, pregnancy, and sometimes after serious trauma (like heterochromia) do represent cause for plausible argument to state that some eyes can or do change, based on chemical reactions and hormonal changes within the body."http://en.wikipedia.org/wiki/Eye_color
this dude did it.
no, they are not contacts.
he used two things:
MSM: which is actually prescriped for the eyes. it is 100% safe
alpha arbutin which is used to stop production of melanin as a skin bleaching agent and is safe for the eye..from what i've read so far