after further thought maybe a form of hydrating sprays that effect the eye, you spray a fine mist and it hydrates the eyes to make the ocular muscles relax? also what about utilizing a form of mild static or electrical shock on ocular muscles? it works on muscle training so perhaps also it can work for myopia? should be much cheaper then dopamine agents.
Stimulating tear production does subjectively seem to reduce my experience of eye strain. Onions may be the exception since they actuay produce an itchy sensation around my eyes.