The vet thinks this has been caused by sudden high blood pressure (she had her well cat check last week and her blood pressure/sight was fine then) and has put her on blood pressure medication. The vet said we'd caught it early and there was a chance the retinas would reattach and she would regain some sight.
Has anyone experienced this? How did your cat cope?
Reading cat sites they say you should keep things calm/quiet, but our kids are all quite small so not great at that and I'm worried they will be stressing her out and keeping her bp up inadvertently.