Taken from my youtube channel and sharing here

Question I love making my own eye's and your tutorials have given me so many different ways to see what works for me. I want to thank you for that. I have a question and I make very small eye's 2mm and 3mm. After I color the iris sometimes its like a tunnel and the color is just all blurred. Then I try not making the hole so deep but when I do I end up with a flat iris and I don't like that effect do you have any suggestions?

I know what your talking about and making that small of an eye your going to run into that problem with certain colors least I did. I found when making them that small I had to place in the iris more high lights I just couldn't do very dark colors like on a larger eye. Just keep in mind that when working on something much smaller it takes less detail and you only put in an illusion.