Where can I find kids spring hinge eyeglasses?

[glass frame]

I need to buy a special pair of prescription eyeglasses for my son, it should be fixed with spring hinge temples, as they can release the pressure of the frame and they prevent you from stretching the fit of your eyeglasses, I just want to know if there are such eyeglasses especially for kids? I have been to several online site, but failed, there were only such option for men! And how much do I need to pay for these eyeglasses?