|MadSci Network: Genetics|
What I think what your friend has is a corneal condition called corneal arcus. It is a relative common condition usually found in folks over the age of 60 and is referred to as arcus senilis. Although this answer is not any sort of diagnosis for your friend, it is what I assume he is referring to as a blue color around his brown (iris) eyes. It may appear slightly blue but is actually a ring of hazy/white deposits on the edge of his corneal and accumulates 360 degrees of the corneal periphery.
This deposit is due to the accumulation of excess cholesterol that deposits there secondary to the aging human body. Other such deposits exists elsewhere in the body as well. If someone under age 55 has these deposits, it may signal a deeper underlying problem with high cholesterol, that may affect the arteries and heart, and put the patient at higher risk for arteriosclerosis, stroke, and hypertension.
As far as predisposition toward African Americans, I have read that it is slightly more common among them then other races in the United States. Also, heart disease, hypertension, and stroke does affect African Americans at a slightly higher rate than Caucasians or Asians. If your friend is under 55 and has this, I would refer him to an internist or his primary care physician for a check-up, including a cholesterol work-up. I hope I have answered your questions and good luck to you!
Kenton McWilliams, O.D.
Cholesterol accumulation in human cornea: evidence that extracellular cholesteryl ester-rich lipid particles deposit independently of foam cells. J Lipid Res. 1996 Sep;37(9):1849-61.
The cornea and disorders of lipid metabolism. Surv Ophthalmol. 1991 Jul-Aug;36(1):1-22.
Try the links in the MadSci Library for more information on Genetics.