Can docs explain what does your vision become like during a stoke?

Depends: Most strokes, vascular occlusions of the brain do not involve vision. But if the occlusion is in the occipital lobe, then up to 1/2 of the total field of view from each eye may be lost. Some strokes affect visual integration such as ability to recognize faces, or to read for instance. You can also get a stroke in the retina of the eye which will cause vision loss.