I am seeing double images and wondering why?

Any sudden onset of double vision needs to be investigated immediately. You need to book an appointment to see your doctor or optician today.

There are a number of causes. Most of them are nothing to worry about, but there are a few serious things that can cause sudden onset of double vision. This can include things like raised pressure in the brain, optic neuritis or any other form of damage to the nerves that supply the eye in order to allow eye movement.

This is the reason why it needs to be investigated promptly, in order to eliminate these things as a possible cause

I have an astigmatism and I used to see double without glasses, over time the double image has gone and now my vision is just fuzzy

are you meaning when your eyes start to cross, or you see like a double outline of something? if yo're talking about a double outline, then what is happening is the color receptors in your eyes have gotten used to seeing one specific color, and when you look away, it shows you something of a "negative" of that color. for instance. looking at red for a long time, then at a white wall will show you a green shape. looking at blue will show you yellow. or something like that, i'm saying this from memory, i'm not sitting here staring at different colors just to tell you which is which... try it sometime

That's the astigamtigism or however its spelled, my brother had the same thing, now he wears glasses and doesn't complain