No, their both izuna'sThat is half correct. One one those eyes were originally Izuna's Mangekyo.
Wait, what happened to Izuna's other eye?
Also, yeah those eyes have passed from one eye socket to another which is kinda gross.
They are both izuna's there no half in this issue.
Izuna's eyes were used, but it was Madara's chakra and body that created the EMS and Rinnegan. Izuna partly helped in the process.