These are the lines one gets around the outward corner of their
eyes when they squint, smile, etc. As one ages, these
lines become
wrinkles, and are
visible even if the skin isn't being smooshed.
This is one of the first signs of your skin aging, along with lines around the mouth. This is because the
skin around the
eyes is thinner, and doesn't have the same
glands as the rest of your
face.
The only way to avoid these is prevention, after they appear they will only go away with very drastic measures like
Botox.