Strabismus refers to any misalignment of the eye. While it usually is evident during childhood, it can develop in adulthood. Eyes may turn inward or outward. One may appear higher or lower than the other. It can affect one or both eyes, and decreases visual performance when the patient compensates to adjust for double vision, poor depth perception, or farsightedness. Surgical modification of the eye muscles are an accepted treatment. Results are improved when the condition is treated very early in life.