I started getting noticeable floaters something like 8-9 years ago. (I see I failed to record it at the time, so I'm estimating now.) Floaters are bits of stuff in the vitreous in your eye that, as the name implies, float around and sometimes get in your way. They don't go away. They were quite annoying at first, but over time they became less invasive -- presumably my brain was learning to ignore them for the most part. I'd still see hem but they didn't get in the way as much.
A few weeks ago I noticed/realized that I've been having more trouble reading lately, whether sitting at a computer or reading a book. It wasn't a sudden change -- not the sudden onslaught that sends one for a same-day appointment to check for retinal detachment. I think it's been building for a while and finally crossed some critical threshold. I couldn't quite tell if the problem was obstruction (what floaters do) or acuity, but I'm not generally having acuity problems.
I had a checkup scheduled for earlier this week anyway, so I asked my ophthalmologist to take a look. She said yup, sure are a lot of floaters and stuff in there. I asked if she could compare what she's seeing now to the last photo she took of the inside of my eye, but that photo didn't help much. She sent me to a retina specialist just to be safe.
I saw that specialist this morning and learned some new things. When he looked in my eyes he said he saw obstructed areas and some haziness (we'll get back to that). So I guess the reason I couldn't tell what the problem was is because it was both? Anyway, today I learned about asteroid hyalosis, which is not actually an astronomical thing but a buildup of stuff in the vitreous. But it's not at all like floaters -- they're a different color and they reflect light, which by the way makes it harder to do eye exams with basic tools. Um, ok. Also, floaters can be, but need not be, caused by torn or detached retinas, while they don't really know what causes asteroid hyalosis. Nor can they do anything about it, unless it gets bad enough to consider extreme remedies. Also, if the hyalosis bits (can I call them asteroids? asteroids in my eye sounds cool) congregate in close proximity they can cause tiny pockets of haziness.
To be safe, though, the retina specialist suggested that they take a detailed scan of my retinas, to which I said sure! He went to talk to the person who would do the scan, and I overheard him say something like "hey, show her the results when you're done; I think she'll be interested in that". (Um, yes, I asked intelligent questions during the exam and used technical terms correctly. I am an active, engaged patient.) The scan was in fact very neat -- it was an optical coherence tomography machine, which spent several minutes per eye taking scans one "layer" at a time using infrared and red light. (Sometimes I saw the light, sometimes I didn't. I'm assuming it wasn't all IR but I didn't ask.) The machine has software that assembles a 3D model based on those pieces, and you can move around inside and look at the retina from different angles. ("What's that dip?" "Your optic nerve." "Oh, now I know how we're oriented!") My maculas look fine too, by the way, which is good. (Of all the vision problems one could have, I think macular degeneration scares me the most -- it's loss of the center of the field.)
One of my assorted eye problems is that (I am told) I was born with crossed eyes (strabismus) and it didn't go away, so I had surgery for it. Probably as a result of that, my eyes have never quite tracked together; sometimes they do, but sometimes my weaker eye goes off to do its own thing, muscularly speaking. (Did that contribute to it being a weaker eye? Unknown.) This especially manifests when I need to use my right eye only to do something, like read an eye chart -- it'll start out fine, but after a couple minutes my eye will start jumping around and I'll have to take a break. I sometimes actually hold my eye in place with my finger (through the lid!) during that part of the exam. Anyway, I mention this to say that staring at the focal point during the OCT scan also caused some ocular rebellion; during the scan I heard the person doing it say to someone else (I think a trainee who was observing him) "we'll have to drop the tracker". The tracker, apparently, is a marker in each scan layer that helps the software knit the layers together properly, I imagine much like the marks that were used in per-color films for color printing back in the day. But the software can still make a decent stab at it even without the tracker working everywhere, based on what I saw.
Having an additional source of occasional random crap in my visual field isn't great, especially since they don't know what causes it or how to keep it at bay, but it's not a sign of something worse and it's an annoyance not a major problem. And I saw some really cool tech in action.