Excellent work. I ranked your originality the lowest, only because I feel that you are practicing creating something real here, instead of drawing something from your imagination. I hope you understand my difference. I don't feel I'm very qualified to comment on technique, as I am not a painter, nor can I draw. I have photographed many eyes, and this is well done.

I understand that you do not have everything perfect as you want to use colour and texture. Also, I can tell you have drawn this with real hands, instead of with shapes created by a program, as the imperfections make a good statement.

The colours are beautiful, and well chosen. It takes close looking at something like an iris to see the depth and variation of colour, I can see that you have done your research (or you have a fantastic memory.)

The upper catchlight is nearly perfect with the lower one, in that they are almost directly across from each other. Often you do not see the second refraction in the eye unless you have a strong direct source of light. In the future, also remember to pay attention to the shape of the light, it will mimic the shape of the light source. As photographers we use this to create interesting shaped catchlights in our subjects eyes, this can really draw a viewer in, often without them noticing why.

I get the feeling looking at this that the light is coming from the bottom right of the image, because of the lighter tones used here on what would be usually a more indented part of the face. However, your catch light presumes that the light is coming from the upper right corner of the image, far enough out that is is not obscured, or only partially obscured, by the eyebrow. This is really the only thing in the image that makes me question the piece. The realism is broken just a little bit by this discrepancy.

The hairs are great, but I feel that the upper eyelashes could be a little longer or curved upwards more. This is personal opinion though, and I understand the way you've drawn it.

Overall this is a very strong piece. It stood out as a thumbnail in your gallery, and made me click through to view it in full.

Compositionally wise, you have a very strong subject in the circular eye. The lines of the brow lead through the circle, and do not exit the page, so they do not pull the eye off of the piece. The white of the eye makes nice negative space around the main subject, giving you a chance to show it off properly. The framing of the flesh tones complement the picture.

The technique you used for the iris mimics life very well, without seeming too perfect. As I mentioned before the imperfections in the piece really make it real to me, and make it stand out as something created by a person, not by a computer.

Good job overall, I really like it.