Intermittent focusing problems after wearing glasses (1 Viewer)

I noticed that I couldn't get a good sharp focus on my bins (any that I tried) from time to time. This seemed to happen at home and not when out birding for the day.
It hasn't been too much of a problem, but was a little concern when I couldn't get a sharp view from my newer bins.
A few weeks ago I had a flight that took a few hours, during which I read a book. I used my new and very cheap off-the-peg reading glasses. After removing the glasses and for long enough to get into the baggage reclaim area, I couldn't focus in the centre of my vision field. If I were to look at someone say 10 to 20yds away their face was quite fuzzy.
I think that my difficult-to-focus events at home probably follow a period of glasses wearing (any PC work).
It must be something that's happening because of the glasses, which I could understand if I experienced some discomfort when using them, but they are perfectly fine.
I know the immediate course of action to take..they are already in the trash, but what were they doing to my eyes to cause this?

Dave

sounds like the reading glasses were causing your eyes to adjust to the glasses ( having worn glasses for over 40 years i know this effect ) and when switching back to non glasses use the eyes can take a while to adjust as they no longer have the "enhanced" vision when you had when using the glasses so your focusing signals to the brain need to readjust. ive found this can take anything from 5 minutes to half an hour.
now though im in the situation where my only needing glasses for Tv and reading is now full time and have to wear varifocals to boot so i dont get the problem so much. however i still notice it first thing in the morning when i wake up it can take a few minutes for my eyes to adjust if i dont put my glasses on straight away and even then everything is a blurry mess and takes a little time to settle in.
using binoculars with varifocals is no fun when trying to track anything as even the slightest movement can put things off kilter.

. It could be that the cheap off-the-peg glasses did not have the correct separation for your IPD. And of course the quality may not be so good.

I do use such glasses for windowshopping, but I only wear them for maybe 10 or 15 minutes. I actually have about five or six of these cheap glasses and only one of them works for me. I've had the usable one for years. The lenses are glass, uncoated and badly scratched, but I still use them. The reason they work well for me is that my two eyes need different dioptre correction. By using same dioptre lenses I gets a large increase in depth of field, because I have little accommodation.

Some people do well with these cheap glasses. One just has to try them and see. At a few pounds they don't break the bank. Of course correctly prescribed glasses are what one should use.

IPD difference is likely, due partly to the style of glasses. The puzzle is that they feel fine in use.

I'd say you probably need glasses more than you think you do.

Dave:

I think you are due for an eye exam from a proper optometrist. You have not said if you wear
glasses or not. I suspect not since you are using reading glasses.

God only gave us only 2 eyes, so take care of them. Watching nature including birds is a gift.
I hope things work out for you.

Jerry

Thanks for your comments. I have no problem after wearing my older (but geeky looking) readers, so hope it was an issue with a couple of pairs of the same glasses.
I had also recently been for my eye test. The results showed no change from the time before, so at least it seems to be stable.
The experience has taught me that perhaps I should have my readers properly made and fitted by the optician. As you say, eyes are too valuable to risk in any way.
I once poked myself in the eye with an eye dropper (the one-shot type that you break the end off to use, so has a sharp open end)
I couldn't focus properly in that eye. the doc told me it would get better over time. It did, but it took several months and during that time I was quite scared of possible permanent damage. Eyes are delicate.
Dave.