Is seeing grey spots in your vision a sign of a tia?

Usually not. The differential diagnosis for "spots" in your vision is varied with the most common cause being floaters secondary to a vitreous detachment. Other causes include orthostatic hypotension changes, ocular migraines, vitreous hemorrhage, and retinal detachment. It is important to get other associated symptoms such as flashes of light. A stroke/tia usually results in total vision loss or greying.