As from your history you are having momentary loss of vision or transient loss of vision.
Transient loss of vision is momentary loss of vision which lasts for few seconds and recovers completely.
It is seen in carotid artery
diseases, as a prodromal symptom of migraine
and other causes characterized by decreased blood supply to the visual pathways.
Please do consult your eye doctor first for confirmation of diagnosis and later physician for further evaluation and treatment.