What causes a sudden black out in vision?

Many things: A number of conditions can cause a sudden blackout of vision. Most of these are vascular events affecting important structions in the visual pathway, such as retinal aretery or vein occlusion, hemorrhages, and vasospasm. We see with both our eyes and our brain, and these structures require perfusion of blood for oxygen, butrition and proper function.

Many causes: Embolic disease (stroke), retinal vascular occlusion, optic neuropathy, retinal detachment, giant cell arteritis, migraine, increased intracranial pressure, ocular ischemia, etc. You must see an ophthalmologist if you have sudden vision loss... Immediately.

Visual migraine: in someone your age, it is usually a visual migraine that will pass in 10-20 minutes. These usually have a geometric pattern to them. A true, sudden black out can also be a transient ischemic attack, or mini stroke. An evaluation by an ophthalmologist is warrented