Ok, I'm seriously stumped. After endless hours of searching and researching, I've found nothing that matches the case of my boyfriend's funky iris.
Basically, he has fairly normal, brown pigmented irises, though if compared to each other they appear to be slightly differing in size and shape. It wasn't until recently, when I took a picture of his unusually dilated pupil (dilated in midday, I may add) that I realized he had a strand of iris fiber stretching across the pupil of his right eye.
I'm not concerned that it's necessarily a disease of his eye. However, I'm concerned it may indicate an underlying problem. The only site I found with an iris with a similar appearance was one dealing in iridology, not something I take too seriously myself. (The site is here: http://cnri.edu/content.asp?contentid=521, and the eye in question is the seventh one down, the "Weak Connective Tissue type - Mesenchymal Pathological Constitution".)
Instead of just explaining it, let me link to actual pictures we've taken:
http://www.hotherym.net/bilder/Photos/Organisms/Drin%20Left%20Iris.jpg 'Normal' left eye.
http://www.hotherym.net/bilder/Photos/Organisms/Drin%20Right%20Iris%2001.jpg 'Abnormal' right eye, also showing what I felt was unusual dilation for the amount of light (which was initially why I snapped the picture).
http://www.hotherym.net/bilder/Photos/Organisms/Drin%20Right%20Iris%2002.jpg Same, but closer, showing the strand more clearly.
http://www.hotherym.net/bilder/Photos/Organisms/Drin%20Right%20Iris%2004.jpg Same eye, with lighting to show the depth of the iris as well.
In addition to his perplexing eye problem, he has a mild pectus excavatum (his mother, however, has a pronounced pectus carinatum), corrected full phimosis, possible low bone density (he breaks his bones easily), somewhat disproportionately large head, mild scoliosis, and an as-of-yet identified golf ball sized and very hard (but movable) tumor near his th1 vertebra, which seems to be causing some displacement. Additionally, he has no 'café au lait' birthmarks, and I pick up on an intermittent click murmur, occasionally with what sounds like a quiet late systolic murmur, when I listen to his heart. I don't know if this will help anyone with experience or with similar symptoms but I felt it was necessary to mention as an aside.
The health community where he resides has been little to no help.
If anyone has any input at all, I'd be incredibly grateful.