Red eye is medically known as infectious conjunctivitis, it is an acute infectious ophthalmia. I can give you some good tips to help your red eyes.
First, keep your eyes clean. Acute conjunctivitis may have many secretions, so it is very important to keep clean. You can use normal saline or 3%boric acid solution to wash your eyes, and then dip eye drops.
Second, in the early period of this symptom, you should cautiously use hormones eye drops, you can have cold compresses, which can help to reduce the swelling. Third, you should avoid stimulation of light and heat, you can wear sunglasses when you go out.