I concur with all previous answers. Pain and especially recurrent pain while exercising is an absolute indication for a need to consult with a doctor. In such a case, I would stop working with that client and obtain a new medical clearance for exercise participation while specifying on the form your client’s signs and symptoms during exercise. I suspect hypertension, possibly in the eye. It could be precursor signs of a stroke. Either way, best not to play doctor and urge your client to see a one before resuming his/her program with you.