The good news
I’ve always been the kind of person who delivers good news. Well, here it is: if the vitreous humor has already been safely separated from the back of the eye, it will not be under tension and will not tear the retina from the back of the eye. So, there is no retinal detachment. This is called PVD (posterior vitreous detachment).
You can think of the interface between the vitreous and the retina like plastic wrap: it’s sticky. If it has already moved away from its normal position where it pushes the retina flat, it will not tear or make holes when it starts to shrink. This type of traction causes a common condition in the ERM, or epiretinal membrane, which can tear in the center of vision on the retina, creating a ‘macular hole’. I’m sure you realize that you don’t want a hole in the middle of your vision. It is possible to self-check this by using an Amsler grid. Wrinkling that occurs at the interface between the retina and the vitreous causes scar tissue to form. To get an idea of how this happens mechanically in the eye, just roll up your sleeve and watch it crinkle.
The bad news
Now we’re onto the bad news. That is, if you have a posterior vitreous detachment (PVD), the floaters in your eyes are more noticeable. In general, floaters are most visible on a bright background that has a lot of contrast.
The most common posterior vitreous detachments form a ring over the optic nerve head. This is called a Weiss ring. The ring shape is caused by release junctions at the edge of the optic nerve head. This ring is often visually significant and is much larger and more condensed than classic floats. The most classic type of eye floaters are stringy with indefinite shapes. Also, a typical eye floater is more mobile than the ring-shaped one. In general, a person who has a posterior vitreous detachment is at increased risk of retinal detachment (RD), this is because they are already experiencing vitreous humor changes.