The symptom you describe is similar to a condition called Amaurosis Fugax
or Transient Monocular Vision
loss. These include a group of conditions, some relatively benign and some not so much. Common causes are a Transient ischaemic attack or stroke, carotid artery stenosis
, ocular disease
, migraine and sometimes unknown. The problem with this is the complaint does not exist at the time the patient visits the ophthalmologist and the retina appears normal. A careful history is important and tests have to be done that evaluate the function of the carotid artery with a carotid doppler, blood tests and even an MRI.It is important to start by visiting your eye doctor who will probably order a few tests to evaluate your condition. General measures to tackle this situation include addressing risk factors like smoking, hypertension, diabetes, obesity ,hypercholesterolemia
and carotid arrythmias.