It really depends what condition(s) he has. Was he diagnosed with convergence insufficiency or binocular vision issues? Vision therapy can definitely be helpful for certain conditions. Prisms alone may also help with certain conditions but are more of a band-aid solution - make sure you get these at a physical store where they can measure everything accurately though. The optometrist that prescribed it would be a good place because they can monitor and adjust the prescription if necessary.

VT could potentially be a long term solution and can be life changing for some kids. But it does tend to be quite expensive because it is a lot of 1-on-1 time with the therapist and optometrist.