If you have the squint, you'd better not wear the contact lenses which may not be good for your eyeballs when you twist your eyes. The bad situation may be that your contact lenses are twisted at the back of the eyeballs. In addition, the ones with trachoma and other eye diseases are not suitable to wear the contact lenses.
Yes, you can wear contact lenses even if you have a squint. In fact, a convergent squint will usually correct just as well with contact lenses as with eyeglasses. But if your vision is really bad in squinting, you may not get help from contact lenses or eyeglasses. So, before you buy contact lenses, you'd better visit an eye doctor and listen to her/his advice.