I think it is a common symptom. I often got my eyes swollen. It will not cause big damage to your eyesight. If you got a cold, you may find that your eyes are a little swollen when you weak up in the morning. If you had cried a lot, you may get the symptom too. You can wash your towel with hot water and then wring them until it will not drop water. Then cover your eyes with the warm towel for few minutes it will make you feel more comfortable. Or get some medications for your cold.
Have you drunk last night? If you did, your swollen eyes may cause by alcohol use. We know that alcohol and tobacco that contain toxins may lead to fatigue, stress, and hormonal changes. They will lead to fluid retention and swelling around our eyes. If you have taken in excess salt, it can encourage fluid retention and may lead to swollen eye too. Oversleeping or interrupted sleep cycles can cause swollen eye. Some of them do really make the symptom prominent.