For basic eye makeup with neutral colors, you could use foundation first. But if you use glitters, shimmers, or a lot of deep-colored eyeshadows, you may experience the pigments falling out and getting stuck on the face. Doing eye makeup first helps keep your face mess-free and clean for the foundation to go on. If you appear to have loose eyeshadow on your face post-foundation, use a Q-tip or cotton swab to wipe off the mess. You could even dip it in makeup remover or cream to pick out glitter bits.