Eye-sprain occurs most often when your unsurprisingly soft human eyes roll so hard ripping backwards and up to zenith so fast that your optical nerves shiver to the point of fraying as after the striking of the imperceptible bridge that connects all of us to the center of life, and a related
as filaments strain
One known cause of I sprain is to be sufficiently human enough to have *occasionally* shaded your eyes from the rear-view, from just that one thing, that they once told your heart to look long and hard at the next time around.
Good eyes are always aware of the hazards. But there are times when their reports must be ignored. Because if you truly wish to "let it happen", you must have the selective ability to absolutely forget to look back, and not heed those old signs - no matter if it looks to you like you wrote that ancient warning to yourself in your own blood.
What is it they say...
Past performance does not necessarily indicate future results.
Yes, that was it. Not always.
Then, you venture your life, in spite of the strain. To remember the past, but not allow it to control what hasn't yet been. To escape your dread, even if you must occasionally and necessarily live it again.
Top: Filaments of the Veil Nebula. This is a vastly old (by frail human standards) supernova remnant coreward along the galactic plane.