编辑同志:我是个老年糖尿病患者,前几天早晨起床时突然觉得眼前发黑,视物不清。被家人急送到医院,医生说是眼中风,幸亏送来得及时,不然会有失明的危险,立即给我治疗,才能看东西了。请问,眼中风是怎么回事?为何如此严重? Edit comrades: I am an elderly diabetic, a few days ago when I woke up suddenly felt black eyesight, blurred vision. Was sent to the hospital by the family, the doctor said it was stroke, thanks to send timely, otherwise there will be the danger of blindness, give me treatment, to see things. Excuse me, what is the problem with stroke? Why is it so serious?