I cannot stress this enough!!
Removing your makeup and washing your face at night is a really important part of skin care that should not be overlooked.
Going to bed with your makeup on consistently will clog your pores and can cause your skin to breakout.
Because we go out during the day, we are exposed to all that pollution. Therefore, if you make it a habit of leaving your makeup overnight and not having some healthy night skin routine, the level of collagen in your skin will decrease and, this might cause your skin to start aging earlier.
As well, make sure you remove your mascara and eyeliner. Those two beauty products stay really close to your eyes all day so, if you sleep with it, it will be a big scare if they go inside your eyes.