That depends on how you get your red eyes. In some cases, red eyes are caused by eye fatigue. Those people who often stay up are likely to get red eyes. In this case, you should wash your red eyes with warm water. Then go to have an enough sleep and then you red eyes will go away when you wake up. If the red eyes are caused by allergies, you may try some eye drops to treat your eye allergies. Just go to see a doctor who will prescrible some eye drops for you to treat your red eyes.
There are many reasons can cause red eyes such as lacks of sleeping, allergies and more. So, i can't give you the accurate answer to clear red eyes.
But you can try to wash your eyes with arm water and get a little sleep. If your red eyes caused by lacking of sleep or eye tired, the red eyes will be clear up.
If this not work, your eyes might be allergies, you need some eye drops that may help. none of them are help, you'd better get your eye checked by an eye doctor to what going on of your eyes.
Normally, the most important thing you can do is to clear your eyes with saline twice or three times a day, and then to drain the water of edge with clean clothes. Also, you can use suitable eye drops to get rid of eye redness. But if your red eyes become more terrible you'd better see a doctor I suppose.