Your mother has suffered with floaters. So has your younger brother. No ill effects so far for either person. They seem to come and go. You can get some basic info, of course, at Wick-or-pedior (http://en.wikipedia.org/wiki/Floater).

Mainly, they are a small annoyance. Under some circumstances, they may be indiciations of serious eye troubles, such as retinal tears. Basically, they might be harmless. Or not. Hope that helps.