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).
Though a lot of people think that twitching eyes are caused by stress or fatigue, the real hidden cause is dry eyes. When eyes are too dry, you involuntarily start blinking to keep them moisturized. After a while, the blinking triggers your nerves and tricks the brain into making your eyes twitch even more.