Can a lazy eye be caused by a hit to the eye?

Maybe. If the injury occured as a young child, it could have led to muscle damage that misaligned the eye, or scar or cataract that blocked the eye's vision. The hit is less likely to be the cause if it occured as an older child or adult. Rarely, an undiagnosed amblyopia can be discovered after an injury brings attention to the eye.
Not usually. If the trauma was severe enough to cause permanent vision loss or dqmage to one of the muscles of the eye, this could lead to the eye drifting out. But usually, there are other causes which are worth having evaluated by an ophthalmologist.