A deviation that is present some of the time tells you something valuable: the visual system still has a mechanism for holding the eyes together, and it is running out of capacity rather than absent.
Control is measurable. Clinicians grade it on how quickly the eye recovers after being covered, how often it drifts spontaneously, and under what conditions it breaks down. A deviation graded as good control at rest but poor after sustained near work is a different clinical problem from one that is constant, and it responds to different treatment.
The practical consequence is that fusion training targets something real here. Widening the range over which the eyes can be held together, and reducing the effort that costs, is exactly the deficit. In a constant deviation with established suppression there is much less to strengthen, which is why the same programme yields much less.
Why It Shows Up After Work
Patients in the Hyderabad technology corridor almost always describe the turn appearing in the evening rather than the morning. That is the signature of a control problem: the mechanism is intact but fatigues under a full day of sustained near and mid-distance screen demand. It is a functional finding, not an inconsistency in the history.