You can get what look like flashes around the periphery of your visual field from just a slightly increased flow of tears. All the same, an optician's opinion would be good, above all to ensure that your retinae are in order. Re PVDs, I have crabbed-age-related PVDs in both eyes, and although they're "interesting" when they're happening, over time they disappear and your eyes revert to more-or-less normal. I do still have a slightly reduced visual field to the lower right, though, but it has never bothered me.