As we know that running is an exercise. There are certain forms of exercise, such as lifting weights and running require straining and cause momentary spikes in your heart rate. Then the strain and increase in blood flow builds up pressure in your head, which causes blood vessels to expand, including those in your eyes. If the pressure is too great, the tiny blood vessels in your eye can burst and make the white part of your eye appear red. You should also know that the more strenuous the exercise is, the greater the amount of pressure that builds in your head. And it will make your eyes redder. For the treatment, after you have a rest, it will disappear, so you don't have to worry about it. Besides, you can also use eye drops to relieve from it. If you still feel bad, you should go and see a doctor so that you can make sure if there are other diseases in your eyes.
Don't worry too much. You should keep using the eyedrops to diminish inflammation for some time. When the symptom declines, you should still use the eyedrops for one more week. And during this time, you should keep good habit of hygiene. Hope this will help you.
Some people's eyes turn to red after strenuous exercises because of higher blood pressure, but it will turn to normal after 1 or 2 hours. That's normal, and don't worry. However, sometimes your eyes will get inflammation with the conjunctivitis, it may caused by the virus that get into your eyes when you running. The sweat may get into your eyes or if you use your dirty hand to rub your eyes. You can relax after running, if after 1-2 hours, the symptom still exists, you may use eye drop for help, if it still can not help, please go to the doctor.
If you do not feel hot in your eyes and do not in a fear of light, and there is not much secretion in your eyes, I think you really do not need worry about it. Maybe they became red because of your running. You just need to have a rest. But if you have the symptoms I mentioned, you should see a doctor. He will prescribe you some eye drops. Besides, you should clean your eyes with normal saline about three times one day. Of course, you should avoid your disease infect others, so you should clean your hands very often and do not let others use your stuff.