It might even happen spontaneously, although probably not as dramatically as that.
My eyes have always subltly changed colour spontaneously in response to hormone levels. When I was a child they were definitely green, as I went through puberty they became first dark brown, and then when I started HRH in my early twenties they became a hazel green, and although this is self observation, and therefore highly unscientific, I notice the shade seems to vary in line with my titrated levels.
(Being a curious type, I have mostly done my own bloodwork and titrations over the last three decades, though under the loose supervision of a GP, so I have indeed got data on this, but without doing a randomised control trial or cohort study, its not strong enough to draw any firm conclusion.)
