I have a little squint in my left eye.sometimes it becomes very visible to others but some times it comes at accurate position.reason?how to cure?

Possibly glasses: Treatment depends on whether the eye is turning in or out. Often the eyes can maintain alignment, but if fatigued, tired, or in some cases speaking or thinking, the eye will drift. You may not be aware except by an observer's reaction. In some cases glasses may help maintain alignment, and rarely eye exercises can help. See an eye care provider with experience in this area to be evaluated.