Some days they are invisible and others, it looks like you could drive a small car through them. We're talking about your pores here people. But is this just an illusion or do they really change sizes day to day?

It's an illusion. The size of your pores is the size of your pores, period. However, they can become engorged with sebum (the oil your skin produces) and build up of dead skin cell. To prevent this and keep them looking small and smooth, try the following:

• A gentle daily exfoliate

• At home microdermabrasion kits

• A pore minimizing serum