Stroke risk from carotid artery blockage

Hello -

I apologize if I'm not asking this in the correct forum.  I had a carotid doppler due to blurred vision.  I was given the results, over the phone, that I have a 49% blockage on both sides, but it is not enough to do anything about.  I was given no advice.  Is this an acceptable amount of blockage for a 49 year old woman? My cholesteral has always been great until recently, when it went up slightly over normal.  There is a strong history of strokes in the females on my mother's side.

Thank you.