When nails have wavy or streaked surface, they can cause cracks. How to deal with them:
To give them a smooth, uniform and luminous look, use the professional nail polisher.
First remove the roughness with step 1, do it in moderation and without much force. Then with step 2 it will give them a beautiful natural glow, in just six passes. And to keep them well hydrated, nourished and without harshness, apply Protein Oil once a day.