What is a floater?

When I use the term “floater,” I am talking about a relative opacity in the vitreous cavity.  The vitreous cavity is the biggest part of the “inside” of the eyeball.  When people are young (e.g. most eight year olds), they have a formed vitreous “jelly” evenly filling that cavity.  Over time, the vitreous changes, and it often starts to look less like an even “jelly” filling the cavity.  So, if there are denser spots or less dense spots or even other things in the cavity, things may not look so homogenous.  These heterogeneities are what I am talking about when I say “floaters.”  There are some things that I am NOT necessarily implying when I say the word, but this can be confusing.  The number one thing that I am not implying is that the opacity moves or “floats.”  Do I mean that there are some “floaters” that don’t “float”?  Yes, that is what I mean.  I also don’t mean to imply any particular shape when I say the word.  “Floaters” can be all different shapes, sizes, colors, etc.  I have talked to many patients who tell me that their symptoms cannot possibly be called “floater” because it doesn’t “float” or it is of a particular shape.  However, I still call them floaters.