Hello, my name is***** and I have over 20 years of experience as a veterinarian. I am very sorry to hear about Lucy's detached retains and sudden blindness and now pink fluid filling the iris area, increased cleaning of her eyes and shaking her head.
Because both eyes are affected it is less likely that this is related to an infection or a mass in her eyes themselves.
In older cats hypertension and secondary bleeding in the back of the eye with retinal detachment is a possible cause and probably the most common cause of sudden blindness. This can be secondary to kidney
or primary heart disease. Rarely it is related to a tumor of the adrenal glands that produces too much of a hormone called aldosterone.
It can also be due to a brain mass placing pressure on the nerves from to he eyes.
Glaucoma (increased intraocular pressure) due to problems draining intraocular fluid is possible as well and one eye can be worse than the other.
If a cat has hypertension and detached retinas eventually we can see bleeding and inflammation in the eye and that can lead to secondary glaucoma as well.
If she is rubbing her eyes and you are seeing bleeding into her eye then it is likely that she has glaucoma, and that is painful, whether it be a primary or secondary form of glaucoma. While it is too late to restore her vision I do think treating her glaucoma to control her pain would be best.
There isn't anything that can be done at home at this point, especially without a diagnosis. If she could see a veterinarian today or tomorrow that would be ideal.
Please let me know if you have any further questions.