I forgot to mention that my other symptoms have been eye twitching and ringing in the ear (both on the same side that I see the light flicker). Are they somehow related?
Vitreous syneresis (liquification of the gel like vitreous) is a normal part of aging. happens to everyone sooner or later. Not a big deal. Posterior vitreous detachment due to syneresis is also a normal part of aging by age 50 one in 2 people have some degree of PVD by age 70 its 3 out of 4. Neither one of those lead to RD with any frequently. The incidence of RD in general populations without special risk factors is only one in about 10,000 to 15,000. Head and neck injuries rarely lead to RD unless the eye was directly struck (e.g. baseball, fist). I doubt the retina specialist said it was 'highly likely" this would lead to RD and suggest you call and ask for clarification. have you eyes checked annually by Eye MD. Sooner if sudden increase of floaters, flash of light or loss of peripheral vision. Seen ENT about rinning in ears (tinnitus).
No it would not cause the tinnitus or twitch (myokymia). Syneresis usually leads to PVD but no way to predict when. I don't understand the 'clean' vs nonclean PVD flickering of light can be a a form a photopsia or light reflex from vitreous movement.
Your activities should be determined by your retina MD who has looked in your eyes and examined you. Flying not problem unless gas in eye. Weight generally mild to moderate high rep okay. Powerlifting to failure not. Cardio walking fine running need to ask
Very very few cause problems at any age, those that do: retinal holes/tears, retinal detachment, vitreous hemorrhage.