# Vision q's - Floaties, -10/-10 and legally blind

1. What are the floaty things in my vision? A friend of mine has them too, and described them better than I can: "Like seeing single-celled organisms and bacteria floating in your vision, if you focus in the proper lighting for a time. Falling with gravity… always falling with gravity. But it looks odd, and I see it no matter where I look, or what I look at. " What’s more, I’ve always had the same floaties–I can tell because one of them’s shaped like a kangaroo.

2. I was recently told I have -10/-10 vision, and I’m wondering what that means. I’m guessing that possibly 0/0 is that point I hit in high school when I stopped being able to see anything clearly without glasses on. 10/10 is being able to see something at 10 yards that someone with perfect vision could see at 20 yards, isn’t it?

3. How blind is legally blind? Because even with -10/-10 vision I’m able to navigate just find, so long as I’m not required to read or go up and down badly lit steps.

Floaters

And welcome to the board!

-10/-10 sounds like the prescription for your glasses, not to be confused with the ‘20/20’ method of determining vision. I can’t see anything 10 ft. behind me…

Just as a reference: Last year, the (uncorrected) vision in my right eye became too bad to measure with numbers, so instead of 20/200, etc., the doctor called it “CF”, for “Counts Fingers” from so many feet away (2, maybe?) Basically, I couldn’t see the biggest letter on the vision chart. My left eye is about 20/700.

I think the -10 stuff is your glasses precription.

Here is an example of a prescription and what the numbers mean:

Cecil on floaters: http://www.straightdope.com/classics/a2_311.html

One interesting part:

Thanks for the floaters info. Maybe I should ask what I’m doing wrong in searching the archives, since I know I searched for vision, blind and legally blind.

My eye doctor also uses the fingers method, which is sort of embarrassing since I know the top letter is always E, I just can’t see it.

The -10/-10 thing is my prescription, sorry. I’m afraid I still don’t understand how that corolates to the 20/20 thing, or where these numbers come from.

Legally blind means that your corrected vision is 20/200 or worse. Since you can apparently see OK with your glasses on, you’re probably not.

Last time my eye doctor asked me what the top letter was, I didn’t even know there was a letter there. I bet I woulda known it was E if I’d thought about it.

Unfortunately, I don’t think it’s possible to directly get a vision reading (the 20/20 stuff) from a prescription. From what I can gather, they

1. Test your eyes to determine the 20/20, etc.
2. Adjust the lenses you’re looking through to look at the chart until you see 20/20 (or as close as possible). They then take the readings for those particular lenses.

I could be completely crazy on this. Any optometrists/opthamologists/etc. care to chime in?

-10/-10 means that both eyes are very nearsighted and require a negative, or diverging, lens of -10 diopters. A diopter is is a unit of focal length used in optometry. -10 means a negative lens with a focal length of 1/10 meter, which is very strong. Mine are on the order of -2.