Diabetes and vision loss; COVID vaccine

I was just going over a chapter in my Physiological Psych textbook, and read about blindsight- that is, cortical regions of the brain involving vision are damaged, but the other visual pathways involving conscious vision still remain intact. Thus, I got to wondering, is this how diabetic neuropathy can lead to vision loss? Cortical apparently references the outer layer of the brain. However, in diabetes, the extra stress would release cortisol that would attack these regions.

*I looked it up online and apparently there are abnormal blood vessels created near the retina that form scar tissue and thus pull the retina away from the back of the eye, resulting in vision loss, or these “lightning strikes”- flashes of light- or floaty, squiggly lines that can disrupt vision.

I remember my dad, as a pre-diabetic, and he has been complaining of something similar- the “squiggly lines” apparently have always been there, but he didn’t start getting the “lightning strikes” (these mainly happen at night while he is driving) until after he got the Pfizer vaccine, and took some ibuprofen for the resulting pain, not knowing that it was not recommended.

Thus, this leads me to a second question- is this the result of taking ibuprofen within the initial window of the vaccine taking effect, or could this be a result of diabetic retinopathy? Or, could taking ibuprofen and the vaccine exacerbate the adverse effects of diabetes? Or is this just a general symptom of the retina disconnecting from the eye, diabetes or not?