I got referred to an ophthalmologist a few years ago when I was getting double vision. She gave me some eye exercises to build up the strength of my eye muscles and they sorted it out for me.
The two main ones I did would be easy for you to try. The first one involved a strip of card about 9 inches long with a line down the middle and a dot on it every inch & a half or so. I had to hold the card horizontally under my nose so that it pointed away fromme, parallel to the ground. I would have to look at the dot furthest away and try and make it so that I saw just one dot. When I'd done that I'd look away for a few seconds and then do the same thing with the next nearest dot, I'd have to repeat this for each dot until I couldn't do it any more.
The other exercise was very similar. I'd hold my my arm straight out in front of me and point my finger up. I'd look at my finger and try to make it so I only saw one finger. Then I'd look away for a few seconds, bring my finger a bit closer to me and then repeat. I'd keep doing this, bringing my finger a bit closer each time.
I'd do these a few times a day. I was warned that I might find the double vision would get worse at first, but that was perfectly normal. It's just like starting going to the gym for the first time - because the muscles have never been exercised like this before, they'll naturally be very tired at first. But they'll start to build up their strength, and then you should start to see an improvement. I only needed to do them for a week or so and I found that I didn't get the double vision any more.
I hope that helps.