Because only when you close your eyes and have a sleep, your eyes will have a break as well. But if you don't have enough sleep, your eyes muscle will always stay nerves. At last, your eyes will become exhausted and hurt. When your eyes hurt, it means your eyes muscle is tied to death. So what you should do is sleep as much as you can. Or you can do massage for your eyes. If you ignore this problem, it will cause headache as well.
When you don't sleep, it easily causes the black circles under your eyes because of the not good blood circulation. In addition, the not well sleep may cause the eyes to be dry. That is the main reason why the eyes feel not comfortable. Thus, owning a good sleep is very important for the healthy eyes.
Well, generally speaking, this kind of symptom comes to many people. So it is very normal to be like this. So you do not need to worry about it too much. In my opinion, it may be because of the eye strain. When you didn't have a good sleep the last night, which means your eyes are still working for the whole night. In that way, it can make your eyes be very tired and also can lead to eye strain. So the next day when you get up and open your eyes, it can be painful for your eyes. And if you often have this kind of symptom, it can lead to some other eye disease, such as dry eyes and water eyes. So just be careful about it and make sure you can have a good sleep. To have a good sleep, you can drink some milk before go to bed. And do not drink tea.