Daily Eye Color Shade Change

I've got a question (obviously) about my eye "problem" (it's not really a problem).

Daily the shade of blue in my eyes changes. When I wake up in the morning (or after I've been asleep for a while) my eyes are DARK blue, but as I am awake they steadily change to a very light blue (almost gray) with a dark ring around the outer perimeter of my iris (sometimes the ring looks almost pewter when the inner part is gray).

This happens to me everyday, and I know it is not because of what I wear, or the current lighting, because I can be in a very bright room right after I wake up and my eyes still look REALLY dark. I have even taken pictures of my eyes right after I wake up and later in the day and there is a very noticeable difference.

I am curious as to why this happens. I've googled it and only have found stuff pertaining to this through aging (as in the change happens over a period of decades). If anyone can help me answer this question then thank you very much.

[John C Hagan III, MD, FACS, FAAO]

Your iris does not change color. Any apparent change of color are due to differences in illumination of the iris and the curvature of your cornea.
JCH MD

[animegirl225]

The illumination of the iris? And how does the curvature of my cornea change?

[John C Hagan III, MD, FACS, FAAO]

It reflects light differently depending on the angle it enters the eye.    Think mood lighting, your cornea may appear on color out doors, a different indoors under fluoriscent light, different incandescent light, difffernt in a dim cafe, etc. The iris may slowly change color over years and years but not daily.

JCH MD

[animegirl225]

That makes a lot of sense, and sounds like it would be the cause. But I kid you not, I can be in my room (lights on) right after I wake up, and my eyes are a really dark blue; then later in the day again in my room (again with lights on) and my eyes will be a very light blue with a dark ring.