Wear sunglasses; covers your eyes.
Take a shower; gives you an excuse to have wet eyes.
Smoke a lot of ****; gives you an excuse to have red eyes.
Tell people you're sick; gives you an excuse to have the sniffles.
Tell people a loved one died; gives you an excuse that's accepted by society.
Don't come out of your room; covers your eyes.
Watch a sad movie; gives you another excuse to cry

Be lonely; won't need an excuse to cry.