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 (amblyopia) is reduced vision in one eye caused by abnormal visual development early in life. The weaker â or lazy â eye often wanders inward or outward. Amblyopia generally develops from birth up to age 7 years. It is the leading cause of decreased vision in one eye among children. Rarely, lazy eye affects both eyes.