My doctor says I have had a detachment. My biggest fear is that I will go blind. You enter the eye by passing through the cornea, the clear covering through which people can see the pupil and iris. The back wall of the anterior chamber is the lens through which light focuses onto the retina. Bits of debris and protein specks fill your vitreous.
Floaters are quite common in nearsighted people.
If the vitreous is so full of floaters that a person is virtually blind, then an eye doctor can replace it with a sterile solution. That operation is not done often. Whenever possible, it is better to live with floaters. I infer that the doctor means a vitreous detachment. The gelatinous material peels away from the back of the eye.