You mentioned a lot being afraid that screen time could be the culprit of your retinal tear. As my doctor said to me, "I am pretty sure you did many things wrong in life, but the membrane (or detachement) is not your fault"

That said, if you are really that concerned with preserving your other eye, I will share with you the precautions I take. First, it is really important to have UV protecting lenses on your glasses. Most are nowadays, but it is worth checking out next time you get a new pair of lenses. This whole blue light stuff is a myth AFAIK. You should be more concerned with excess light, contrast and strain. Please for the love of god avoid working on these tiny 13 inches macbooks, get yourself a decently sized monitor, configure your OS to zoom things to something like 125% and keep the brightness level as low as you can take it to match the room you are. The goal here is to have a comfortable workspace in which you don't have to force your eyes and they take as much light from the screen as they take from everything else around you. It is not about "less screen time" but making screens not be blasts of light that you have to focus on tiny micro letters.