ionization energy is the energy required to remove the electron of an atom? ?.right?metals generally have positive charges.so the attraction between the postively charged nucleus and its valence electrons will be really strongso it will have high ionization energyhigher ionisation energy will result in higher electronegativity..but metals generally are electro positive? ?.
Metal frames are more comfortable and they last longer/don't break as easily. I'm sure you could find a pair of metal frames that look like the plastic ones.
Comfort to me is always a priority since they are worn a lot. I would choose metal.
