Very well done for your first eye attempt! Digital can take some getting used to, but one of the best ways to familiarize yourself with any new medium is to practice black and white studies, as in this case. Even so, trying it out on newsprint is also a good option, as practicing traditionally gives you a solid foundation before moving onto digital. As you continue your practice, something to note here would be that the area of the iris and pupil could be larger, and that the lower eyelid should be thinner and taper as it reaches the tear duct opening, to give the illusion that it's wrapping around a sphere. I do think you did a good job organizing your values and showing the structure making up the eye, so it's just a matter of gaining more control with the medium of your choice to reach more value clarity, especially in the half-tones, which will come with practice. Keep up the good work :)