When I Smile my Cheeks Cover Part of my Eyes, What Can I Do?

Hello, I really don't like my smile. It pushes my lower eyelids up and makes my eyes smaller. I am underweight so it is not a weight issue. At first I thought it was normal for the eyes to become smaller when you smile but I analyzed other people's pictures and their eyes don't get as small as mine (or some don't even get small at all). What can I do? (I am 21 years old. I figure my baby fat has been long gone?) Thank you!