I had a second opinion as you advised and was told while I do have a slight vertical convergence misalignment, I've been repeatedly told that it cannot be my problem here as I do not have binocular vision. Since childhood I have had "monovision" where one eye was used for distance and one for close. Over time as distance vision decreased in the distance eye I just wore one contact lens, and eventually had Lasik surgery in that one eye. Any attempt to correct both eyes results in double vision and bad strain so severe I was told even if I had binocular vision they'd not expect therapy to fix it and prisms would be required.
Somehow my body "chose" monovision to deal with this imbalance 30+ years ago. It's never been a problem for me, always had fine peripheral vision and no issues. Every doctor has said leave it alone as trying to correct and create good binocular vision adds problems for me. I don't know if it's connected to this but feels doubtful since I can get on this 12yo laptop and sit at it 12+ hours until every bone aches, or read all day, or do whatever else and my only visual problem is presbyopia from old man eyes trying to read small labels etc...but I have no strain in any scenario other than modern LED backlights. If it was as simple as my eyes being the problem I'd have it in multiple settings. Doctor suggested a single lens reading glasses for the left eye which has presbyopia now due to age but I already tried that and it didn't work. Not paying hundreds of USD again for that.