Chronic pain: Pain (an unpleasant sense of discomfort) that persists or progresses over a long period of time. In contrast to acute pain that arises suddenly in response to a specific injury and is usually treatable, chronic pain persists over time and is often resistant to medical treatments.
Common causes of the condition include: 1  Muscle imbalance (strabismus). The most common cause of lazy eye is an imbalance in the muscles that position the eyes. 2  Difference in sharpness of vision between the eyes (refractive anisometropia).
Lazy eye is related to developmental problems in your brain. In this case, the nerve pathways in your brain that process sight donât function properly. This dysfunction occurs when your eyes donât receive equal amounts of use. A number of conditions and factors can lead you to rely on one eye more than the other.