pejalo
Yes, I tried plus power lenses, they actually make my symptoms worse.
Though it's an excellent question because now I perfectly know why and I would like to share it with you here. When it's heterophoria that is the culprit of symptoms, your eyes try to "mask" your binocular vision issues by your accommodation. That's why many of us complain of blurred vision among arising symptoms.
It's a huge discovery to me that if you do the cover test (one of the principal heterophoria measurement method) with your accommodation excluded your result may be completely different from one when your accommodation is "turned on". I mentioned in this thread that my exophoria was 14, but it's actually 21-25 when my accommodation is loosened.
How to loose your accommodation? It can be simply done by wearing +3D lenses.
By the way, this also provides the final answer for the title question I asked almost a year ago. It's not a spasm of accommodation itself. It's my exophoria that brings the spasm of acc.
pejalo I get weird feelings of warmth from my vision being off
I'm surprised, but kind of glad to read this because I also have these feelings of warmth. Now I'm 100% sure they come from my vision, but everyone was telling me it was stress related. Could you describe these feelings a bit more? Where are they located, what parts of your body? By the way, did you test your binocular vision?