Eye / vessel damage from quickly reducing BG

I think that the blurry vision is something different and it corrects itself fairly quickly.
It is due to the concentration of glucose in the fluids within the eye altering faster than the lens can adapt.

There are numerous eye conditions that can develop due to lowering of levels too quickly, 2 I've suffered personally from because of it were diabetic macular oedema and proliferative retinopathy xx

I had a marked deterioration of vision in one eye was diagnosed with retinal vein occlusion in 2019 whether that was related to low carbing I really dont know. I had two courses of Lucentis injections and was due to be reviewed a year ago but I guess because of Covid everything is delayed.

Don't know whether we are talking about the same condition, but temporary blurred vision after lowing your blood sugars is common. Don't have a proper reference, but there is a quick mention of this at https://www.healthline.com/health/diabetes/blurry-vision

You may also get blurred vision when you start insulin treatment. This is due to shifting fluids, but it generally resolves after a few weeks. For many people, as blood sugar levels stabilize, so does their vision.

I've experienced this, both when I initially went on metformin and also when I was switched to insulin.
The way it was described to me was that when your blood sugar was high, some sugar molecules entered your eye fluid, which can causing some blurring. As more entered, some got stuck to the edges of your eye. Here they were out of the way and did not cause the blurred vision (but did cause other problems).
When your blood sugar levels start to come down again, all these molecules detach from the edges and re-enter the eye fluid and so it is the increased numbers that causes the blurred vision to get worse. The number of sugar molecules starts to decrease and so after a number of weeks the vision normally goes back to normal.

I'm hoping this is what you are thinking of, as it is a lot less serious than "fractured blood vessels."

Temporary blurring of vision can occur when blood glucose levels are normalised due to changes in the refraction in the eye. It can take a few weeks to resolve so people should not buy new prescription glasses until their vision is stable.
https://www.researchgate.net/public...tients_with_newly_diagnosed_diabetes_mellitus

A temporary worsening of diabetic retinopathy can occur when people improve their blood glucose control after a period of poor control - this may require treatment, although blurriness of vision may not be involved. http://www.diabeticretinopathy.org.uk/rapidprogression.html

The medical term for the temporary blurriness is 'transient hyperopia', and although it has been known about since the 19th century the precise mechanisms are still not fully understood.

The degree and duration have been correlated to the HbA1c before diagnosis and the rapidity of glucose control. The mean effect on sight typically peaks around 1.5 dioptres but easily can be over 3.

The key word though is transient. Four weeks typically, six not being unusual. Tends to tail off more slowly than it develops. Most people end back with eyesight fairly similar to before but there can be permanent changes more rarely.

I went cold turkey and the blurred vision righted itself within a very short timescale. I only learned about it on this forum (when I could read again!) and with hindsight would have been better to have tackled lowering BG more slowly, but the likelihood was never mentioned (not much info was given at all) and - lucky me - no permanent damage resulted.