If your eyes get painful, you may get serious problem. Your redness of the eyes is caused by your infection from the invisible bacterium. Or your long time use of eyes in front of the computers could also cause your eyes to get red. You could use the eye drops with anti-inflammation to release it. At the same time, you need to have the good rest.
Well, according to some researches, red eyes are caused by the enlarged and dilated blood vessels in the surface of the eye which has become irritated. Of course, you need to know that it could be a medical emergency or a non-emergency. In daily life, the most common causes of red eyes are irritants such as pet dander, blowing wind, dry air and sun exposure. And lacking of sleep can be the cause too. If contact lenses are worn for too long, they can experience red eyes too. So for your situation, it is very difficult to tell what the real cause is. And you can just go and see the eye doctor.
Since your eyes are red but not painful, you need not worry about it. There are many reasons for your present condition. If you are a contact lenses wearer, it is probably because that the contact lenses you wear have irritated your eyes. So you should stop wearing contact lenses. If you have been taking a certain medicine, it may be the medicine that makes your eyes bloodshot. When you are allergic to something, your eyes may also be affected by the allergen thus become red. If you are alleviated from the allergy, the eye redness will also disappear. Your red eyes may be the result of the changing pressure that makes the blood vessels in eyes to burst. Besides, the change in hormones can also leads to bloodshot eyes.