Well, generally speaking, it is very normal to have this kind of disease in your eyes. And the veins are normal and they happen in every people's eye. It may just appear more prominent in some situation. And when it happens, you can just try some ways to treat it. For example, you can try some lubrication eye drops which can be helpful to the symptom. Also, you should drink more water so that it can relieve the symptoms or just have good rest so that they will go away. If they still exist, you should go and see the doctor, and maybe he can just tell you what to do.