More often than not, a combination of surgery and exercises yield the best outcomes. This is the tendency for the eyes to be turned in, but the eye muscles can overcome the deficit. As with exophoria, this extra effort can cause eyestrain. Sometimes the problem is caused merely by the need for hyperopia correction and eyeglasses or contact lenses fix the problem. But sometimes eye exercises to help re-train the eyes to function more appropriately can work, especially when combined with the proper vision correction.
Phoria conditions are more easily remedied with exercises than tropia conditions.
Both require careful diagnosis and evaluation of the problem and specially tailored vision therapy programs. The discussion for exo and eso conditions applies here as well. The six muscles that move each eye must work in a coordinated fashion so that we can change our vision from one point in space to another smoothly and quickly. Sometimes one or more of the muscles does not work with maximum efficiency and our eyes do not move to the new position quickly enough for good vision system comfort. Or worse, with children, the eyes may not be able to track smoothly across the printed page, or may loose position when returning to the next line down on the page.