I have a hard, polycarbonate globe, like this one pictured below. I am trying to make it look like an eyeball. I am lighting it from inside, and I already have a good blue iris that I made out of blue gel sheets. The problem is, it only looks like an eyeball when the light is on, and it is not too bright outside. When the light is off, it looks like a white sphere.
So, I'd like to dye an iris shape on the outside of the globe. But everything I'm reading seems to say that you can't dye this kind of plastic. Is that correct? Or is there some way?
(I've tried painting the outside, but when light is shining through, every little brushstroke stands out, and it looks awful)