My friend went dead for like 10 seconds

My friend and I were talking and laughing and then when he was in the middle of a sentence his eyes stopped moving, and they went black. He is a white guy and he literally went dead for 10 seconds and then came back to life. It was kind of creepy but I forgot about it. Then the next day it happened again but when he came back to normal his eyes turned RED so my dad took him to the hospital and he was fine. The doctor said that it could be some genetic thing he got from his father, but his father didn’t have this condition.