My Mom last week had a black spot in her eye which totally freaked her out..she always worries about retina detachment(Her doc told her it might happen since she has the film on her eye) so she went to the doc and he told her her retina is fine..also told her(Since she was also concerned about a mini stroke) that someone who has a mini stroke will have the entire eye black and wont go away after a few minutes like hers did..that what she had was a migraine
Not sure what your Mom’s “black” description is but when my wife casually told me her right eye was “going black” - little or no vision and her Opthamolgists nurses said nothing I had her go see the Eye Doc with a 3x5 listing her symptoms so she’d cover them all.
Turns out her carotid artery was 99% blocked - confirmed by a specialist down the hall.
The Doc even called me while she was on her way home from her appointment and told me to pack her bags and get her to the ER as soon as she got home (Friday afternoon).
So she spent the weekend on blood thinners and maybe this or that and got cleaned out on Monday.
Something I’d get checked right away. Not a Doc but hope this helps.
All turned out well - she’s a diabetic but got off insulin years ago with very good sugar control with a ridiculous diet and exercise but it can be done.
Just no carbs or milk products. That means no bread, pasta, chips, crackers, most fruits or juices, no sugars, etc. etc.
Anyone can ask and I’d detail her diet - I personally think there’s a book there. ;-)