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).
Eye Twitching, also known as blepharospasm or myokymia, is a sudden, involuntary movement of the eyelid; it is also referred to as an eye muscle spasm. These spasms often occur in stressful situations or when the affected individual has gone too long without sufficient rest.ther common eye twitch causes include: 1  Stress. 2  Irritation of the Cornea or Conjunctiva. 3  Fatigue/Lack of sleep. 4  Prolonged staring at a computer screen or television. 5  Excessive caffeine intake (e.g., coffee, tea, caffeinated sodas). 6  Nervous system disorders.