Should I get a third opinion?

Approximately one month ago I started having flashes in the corner of one of my eyes, no new floaters or anything but I was still pretty freaked out so I scheduled an emergency appointment and went to an eye clinic. I don't have a very high prescription; -2.50D and -3.25D last time I checked (which was two years ago, I know I should have gone sooner). Anyway, they looked at my retina and there was nothing unusual; I was told it was probably my vitreous gel pulling away from it. Also, they told me my eyes are -3.00 D and -3.75 D now.

After a few weeks I thought it was a good idea to schedule another appointment, to get a second opinion, just in case. I still have flashes but more sparsely and no new symptoms. This time I was told I was overprescribed and that I am actually a -1.75 D, -3.25 D but how can that be? It's true that I can still see perfectly with the old -2.50 prescription, but -1.75 seems so low, my other eye has indeed gotten worse so -3.25 is not enough…also, I was told my retina will be checked in a separate appointment, after I get my new glasses; they didn't think it was necessary now. Should I get a third opinion?

Edit; I found my old prescription from 2 years ago, I was remembering the numbers wrong so I changed them.