:} The iris is a beauty to work with and the only other thing I might suggest to further increase the realism of the eyeball would be to try for a bit of translucency...also the sharpness of where the colored iris meets the white of the eyeball could be very slightly softened and a bit of transparency effect like you can sorta see into that area. The clear cornea area in actuality sits a bit on top of the white. Then there's tiny blood vessels which you may or may not include depending on how real you want to take it. More sharp highlites of the white part would also make it look shinier. Anyway, just some ideas. It looks fabulous as is too!
:} Fun eyedea! Run with it, you've got the best looking eyeball around, better than any I've seen done anywhere, and there's no end to what you can do with it! Yep, your PS talents will make ya $$$ too!
Maybe at some point you might consider putting up your own website if you haven't already??? Then also maybe decide what your main goal and focus will be using your artwork cause there's so many things you can do with it. Do you want to use it for illustrating? Perhaps books, bookcovers, etc., or produce your own illustrated book on some theme? Or get into advertising media -- work for a magazine, or paper, or do freelance work for various companies (good to have a website to advertise what you will be doing and to draw clients), or use your skills in addition to even other media like film, 3d (there's a wide variety of things you could do using your PS skills -- you've got a very good eye, Patrick, that lends itself to creating anything needing realistic textures and designwork and lighting besides any other artwork type you want to do). Or do you want to just do freelance and produce stand alone artwork pieces?
Anyway, when you have an area you want to pursue then you can plan the route to take next. You could hunt around your town/city for work in a graphics studio -- get your foot in the door and then take it from there. With the right attitude you can accomplish ANYTHING. Start advertising what you can do everywhere, tell everyone, keep some samples with you at all times -- you never know who you will meet next time you step out that door. You have to do your PR work and like with any business endeavor -- NETWORK. Connections are what help tremendously and there's only one way to make them = get your work out there and meet people. You've got everything it takes.
I think you have a remarkable start as a digital artist, at 16 already!
My suggestion is a simple one. Keep creating for fascination, enjoyment, and the joy of it. As your already fine skills progress, people will take notice. In time opportunities will be offered without your having to do any 'selling' of your skills. You will just be for real.
The great joy of progressing in that fashion is that you never have to exaggerate, pretend, or posture that you are something you are not. You will be able to have people come to you for who you are and what you do. In short, be the creator of your own existence. It's a great goal, and seldom attained.