The Grandfathering Program for drivers participating in the diabetes and vision waiver study program of March 31, 1996 excluded these drivers from the regulatory requirements of 391.41 (b) (3) and 391.41 (b) (10), respectively.   These drivers must be qualified otherwise under 391.41 except for Insulin Treated Diabetes Mellitus or the inability to meet the vision standard in one eye.  The provisions of the program is described in the immediate link that follows.   Also, the second link is a report which describes the studies that looked at the feasibility of  insulin treated diabetes and commercial driving.

http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=391.64

http://www.fmcsa.dot.gov/facts-research/research-technology/tech/TB-02-01-1.htm