Strabismus is the correct term for any misalignment of the eyes. It is often called a squint, a crossed eye, or a turn in the eye. There are many different types.
Strabismus is usually categorised according to the direction of the turn. An inward (converging) turn is called an esotropia. An outward (diverging) turning eye is called an exotropia.
Vertical strabismus occurs when the eye turns downwards, called a hypotropia, or upwards, called a hypertropia. It is also possible but much less common for the eye to be twisted out or in. This is known as a cyclotropia.
Strabismus can occur in childhood or adulthood, depending on the cause.