In my opinion, I think it's genetics. I visited one of my LFS and noticed that all of his new stock of silvers have Drop eye on their right eye. Possibly due to improper breeding.
we've been thru this arguement to many times in the past year and a half lol
the statement "i never see wild aros with drop eye"
how many wild aros have you observed and compared with eachother or with captive bred aros?
i dont care for crap about DE, its just halarious to me to watch every new person in the books that signs up for MFK to try and figure out what the cause is, or exactly what it is, or how to get rid of it. learn to live with it, its been this way for over 40 years and always will be lol