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).
A twitching eye can be one sign of stress, especially when it is related to vision problems such as eye strain (see below). Reducing the cause of the stress can help make the twitching stop. Tiredness: A lack of sleep, whether because of stress or some other reason, can trigger a twitching eyelid. Catching up on your sleep can help.