16 is not too old. Neurobiologist Susan Barry fixed it at 40 years old. I would find an optometrist who specializes in vision therapy who also has an open mind about surgery. Like others have said it all depends what type of strabismus you have.
There are different types of strabismus which may need different types of vision therapy. So you'd better find a developmental optometrist who specializes in strabismus and let him check your eyes. Then he will know which type of vision therapy can treat your strabismus.
It should depend on types of strabismus you have and how your brain can make to each type. The best way is to find a developmental optometrist that specializes in strabismus, and have your vision evaluated.