polycarbonate glasses are impact resistant, so they are usually used for sports and children use. However, they can be scratched easily. If you want to buy polycarbonate glasses, you can ask your optician to add scratch-resistant coating to the lenses so that they won't get scratch easily.
Yes, it is true. Polycarbonate can get scratched even you are cleaning them. Some people scratch their lenses by cleaning them with paper towel. So you should be much careful with the polycarbonate lens and it is better to add an anti-scratch coating on it.